1alternate object database:: 2 Via the alternates mechanism, a repository can inherit part of its 3 object database from another object database, which is called 4 "alternate". 5 6bare repository:: 7 A bare repository is normally an appropriately named 8 directory with a `.git` suffix that does not have a 9 locally checked-out copy of any of the files under revision 10 control. That is, all of the `git` administrative and 11 control files that would normally be present in the 12 hidden `.git` sub-directory are directly present in 13 the `repository.git` directory instead, and no other files 14 are present and checked out. Usually publishers of public 15 repositories make bare repositories available. 16 17blob object:: 18 Untyped object, e.g. the contents of a file. 19 20branch:: 21 A non-cyclical graph of revisions, i.e. the complete history of 22 a particular revision, which is called the branch head. The 23 branch heads are stored in `$GIT_DIR/refs/heads/`. 24 25cache:: 26 Obsolete for: index. 27 28chain:: 29 A list of objects, where each object in the list contains a 30 reference to its successor (for example, the successor of a commit 31 could be one of its parents). 32 33changeset:: 34 BitKeeper/cvsps speak for "commit". Since git does not store 35 changes, but states, it really does not make sense to use 36 the term "changesets" with git. 37 38checkout:: 39 The action of updating the working tree to a revision which was 40 stored in the object database. 41 42cherry-picking:: 43 In SCM jargon, "cherry pick" means to choose a subset of 44 changes out of a series of changes (typically commits) 45 and record them as a new series of changes on top of 46 different codebase. In GIT, this is performed by 47 "git cherry-pick" command to extract the change 48 introduced by an existing commit and to record it based 49 on the tip of the current branch as a new commit. 50 51clean:: 52 A working tree is clean, if it corresponds to the revision 53 referenced by the current head. Also see "dirty". 54 55commit:: 56 As a verb: The action of storing the current state of the index in the 57 object database. The result is a revision. 58 As a noun: Short hand for commit object. 59 60commit object:: 61 An object which contains the information about a particular 62 revision, such as parents, committer, author, date and the 63 tree object which corresponds to the top directory of the 64 stored revision. 65 66core git:: 67 Fundamental data structures and utilities of git. Exposes only 68 limited source code management tools. 69 70DAG:: 71 Directed acyclic graph. The commit objects form a directed acyclic 72 graph, because they have parents (directed), and the graph of commit 73 objects is acyclic (there is no chain which begins and ends with the 74 same object). 75 76dircache:: 77 You are *waaaaay* behind. 78 79dirty:: 80 A working tree is said to be dirty if it contains modifications 81 which have not been committed to the current branch. 82 83directory:: 84 The list you get with "ls" :-) 85 86ent:: 87 Favorite synonym to "tree-ish" by some total geeks. See 88 `http://en.wikipedia.org/wiki/Ent_(Middle-earth)` for an in-depth 89 explanation. Avoid this term, not to confuse people. 90 91fast forward:: 92 A fast-forward is a special type of merge where you have 93 a revision and you are "merging" another branch's changes 94 that happen to be a descendant of what you have. 95 In such these cases, you do not make a new merge commit but 96 instead just update to his revision. This will happen 97 frequently on a tracking branch of a remote repository. 98 99fetch:: 100 Fetching a branch means to get the branch's head ref from a 101 remote repository, to find out which objects are missing from 102 the local object database, and to get them, too. 103 104file system:: 105 Linus Torvalds originally designed git to be a user space file 106 system, i.e. the infrastructure to hold files and directories. 107 That ensured the efficiency and speed of git. 108 109git archive:: 110 Synonym for repository (for arch people). 111 112grafts:: 113 Grafts enables two otherwise different lines of development to be 114 joined together by recording fake ancestry information for commits. 115 This way you can make git pretend the set of parents a commit 116 has is different from what was recorded when the commit was created. 117 Configured via the `.git/info/grafts` file. 118 119hash:: 120 In git's context, synonym to object name. 121 122head:: 123 The top of a branch. It contains a ref to the corresponding 124 commit object. 125 126head ref:: 127 A ref pointing to a head. Often, this is abbreviated to "head". 128 Head refs are stored in `$GIT_DIR/refs/heads/`. 129 130hook:: 131 During the normal execution of several git commands, 132 call-outs are made to optional scripts that allow 133 a developer to add functionality or checking. 134 Typically, the hooks allow for a command to be pre-verified 135 and potentially aborted, and allow for a post-notification 136 after the operation is done. 137 The hook scripts are found in the `$GIT_DIR/hooks/` directory, 138 and are enabled by simply making them executable. 139 140index:: 141 A collection of files with stat information, whose contents are 142 stored as objects. The index is a stored version of your working 143 tree. Truth be told, it can also contain a second, and even a third 144 version of a working tree, which are used when merging. 145 146index entry:: 147 The information regarding a particular file, stored in the index. 148 An index entry can be unmerged, if a merge was started, but not 149 yet finished (i.e. if the index contains multiple versions of 150 that file). 151 152master:: 153 The default development branch. Whenever you create a git 154 repository, a branch named "master" is created, and becomes 155 the active branch. In most cases, this contains the local 156 development, though that is purely conventional and not required. 157 158merge:: 159 To merge branches means to try to accumulate the changes since a 160 common ancestor and apply them to the first branch. An automatic 161 merge uses heuristics to accomplish that. Evidently, an automatic 162 merge can fail. 163 164object:: 165 The unit of storage in git. It is uniquely identified by 166 the SHA1 of its contents. Consequently, an object can not 167 be changed. 168 169object database:: 170 Stores a set of "objects", and an individual object is identified 171 by its object name. The objects usually live in `$GIT_DIR/objects/`. 172 173object identifier:: 174 Synonym for object name. 175 176object name:: 177 The unique identifier of an object. The hash of the object's contents 178 using the Secure Hash Algorithm 1 and usually represented by the 40 179 character hexadecimal encoding of the hash of the object (possibly 180 followed by a white space). 181 182object type:: 183 One of the identifiers "commit","tree","tag" and "blob" describing 184 the type of an object. 185 186octopus:: 187 To merge more than two branches. Also denotes an intelligent 188 predator. 189 190origin:: 191 The default upstream tracking branch. Most projects have at 192 least one upstream project which they track. By default 193 'origin' is used for that purpose. New upstream updates 194 will be fetched into this branch; you should never commit 195 to it yourself. 196 197pack:: 198 A set of objects which have been compressed into one file (to save 199 space or to transmit them efficiently). 200 201pack index:: 202 The list of identifiers, and other information, of the objects in a 203 pack, to assist in efficiently accessing the contents of a pack. 204 205parent:: 206 A commit object contains a (possibly empty) list of the logical 207 predecessor(s) in the line of development, i.e. its parents. 208 209pickaxe:: 210 The term pickaxe refers to an option to the diffcore routines 211 that help select changes that add or delete a given text string. 212 With the --pickaxe-all option, it can be used to view the 213 full changeset that introduced or removed, say, a particular 214 line of text. See gitlink:git-diff[1]. 215 216plumbing:: 217 Cute name for core git. 218 219porcelain:: 220 Cute name for programs and program suites depending on core git, 221 presenting a high level access to core git. Porcelains expose 222 more of a SCM interface than the plumbing. 223 224pull:: 225 Pulling a branch means to fetch it and merge it. 226 227push:: 228 Pushing a branch means to get the branch's head ref from a remote 229 repository, find out if it is an ancestor to the branch's local 230 head ref is a direct, and in that case, putting all objects, which 231 are reachable from the local head ref, and which are missing from 232 the remote repository, into the remote object database, and updating 233 the remote head ref. If the remote head is not an ancestor to the 234 local head, the push fails. 235 236reachable:: 237 An object is reachable from a ref/commit/tree/tag, if there is a 238 chain leading from the latter to the former. 239 240rebase:: 241 To clean a branch by starting from the head of the main line of 242 development ("master"), and reapply the (possibly cherry-picked) 243 changes from that branch. 244 245ref:: 246 A 40-byte hex representation of a SHA1 or a name that denotes 247 a particular object. These may be stored in `$GIT_DIR/refs/`. 248 249refspec:: 250 A refspec is used by fetch and push to describe the mapping 251 between remote ref and local ref. They are combined with 252 a colon in the format <src>:<dst>, preceded by an optional 253 plus sign, +. For example: 254 `git fetch $URL refs/heads/master:refs/heads/origin` 255 means "grab the master branch head from the $URL and store 256 it as my origin branch head". 257 And `git push $URL refs/heads/master:refs/heads/to-upstream` 258 means "publish my master branch head as to-upstream master head 259 at $URL". See also gitlink:git-push[1] 260 261repository:: 262 A collection of refs together with an object database containing 263 all objects, which are reachable from the refs, possibly accompanied 264 by meta data from one or more porcelains. A repository can 265 share an object database with other repositories. 266 267resolve:: 268 The action of fixing up manually what a failed automatic merge 269 left behind. 270 271revision:: 272 A particular state of files and directories which was stored in 273 the object database. It is referenced by a commit object. 274 275rewind:: 276 To throw away part of the development, i.e. to assign the head to 277 an earlier revision. 278 279SCM:: 280 Source code management (tool). 281 282SHA1:: 283 Synonym for object name. 284 285symref:: 286 Symbolic reference: instead of containing the SHA1 id itself, it 287 is of the format 'ref: refs/some/thing' and when referenced, it 288 recursively dereferences to this reference. 'HEAD' is a prime 289 example of a symref. Symbolic references are manipulated with 290 the gitlink:git-symbolic-ref[1] command. 291 292topic branch:: 293 A regular git branch that is used by a developer to 294 identify a conceptual line of development. Since branches 295 are very easy and inexpensive, it is often desirable to 296 have several small branches that each contain very well 297 defined concepts or small incremental yet related changes. 298 299tracking branch:: 300 A regular git branch that is used to follow changes from 301 another repository. A tracking branch should not contain 302 direct modifications or have local commits made to it. 303 A tracking branch can usually be identified as the 304 right-hand-side ref in a Pull: refspec. 305 306tree object:: 307 An object containing a list of file names and modes along with refs 308 to the associated blob and/or tree objects. A tree is equivalent 309 to a directory. 310 311tree:: 312 Either a working tree, or a tree object together with the 313 dependent blob and tree objects (i.e. a stored representation 314 of a working tree). 315 316tree-ish:: 317 A ref pointing to either a commit object, a tree object, or a 318 tag object pointing to a tag or commit or tree object. 319 320tag object:: 321 An object containing a ref pointing to another object, which can 322 contain a message just like a commit object. It can also 323 contain a (PGP) signature, in which case it is called a "signed 324 tag object". 325 326tag:: 327 A ref pointing to a tag or commit object. In contrast to a head, 328 a tag is not changed by a commit. Tags (not tag objects) are 329 stored in `$GIT_DIR/refs/tags/`. A git tag has nothing to do with 330 a Lisp tag (which is called object type in git's context). 331 A tag is most typically used to mark a particular point in the 332 commit ancestry chain. 333 334unmerged index:: 335 An index which contains unmerged index entries. 336 337working tree:: 338 The set of files and directories currently being worked on, 339 i.e. you can work in your working tree without using git at all. 340