1object:: 2 The unit of storage in git. It is uniquely identified by 3 the SHA1 of its contents. Consequently, an object can not 4 be changed. 5 6object name:: 7 The unique identifier of an object. The hash of the object's contents 8 using the Secure Hash Algorithm 1 and usually represented by the 40 9 character hexadecimal encoding of the hash of the object (possibly 10 followed by a white space). 11 12SHA1:: 13 Synonym for object name. 14 15object identifier:: 16 Synonym for object name. 17 18hash:: 19 In git's context, synonym to object name. 20 21object database:: 22 Stores a set of "objects", and an individual object is identified 23 by its object name. The objects usually live in `$GIT_DIR/objects/`. 24 25blob object:: 26 Untyped object, e.g. the contents of a file. 27 28tree object:: 29 An object containing a list of file names and modes along with refs 30 to the associated blob and/or tree objects. A tree is equivalent 31 to a directory. 32 33tree:: 34 Either a working tree, or a tree object together with the 35 dependent blob and tree objects (i.e. a stored representation 36 of a working tree). 37 38DAG:: 39 Directed acyclic graph. The commit objects form a directed acyclic 40 graph, because they have parents (directed), and the graph of commit 41 objects is acyclic (there is no chain which begins and ends with the 42 same object). 43 44index:: 45 A collection of files with stat information, whose contents are 46 stored as objects. The index is a stored version of your working 47 tree. Truth be told, it can also contain a second, and even a third 48 version of a working tree, which are used when merging. 49 50index entry:: 51 The information regarding a particular file, stored in the index. 52 An index entry can be unmerged, if a merge was started, but not 53 yet finished (i.e. if the index contains multiple versions of 54 that file). 55 56unmerged index: 57 An index which contains unmerged index entries. 58 59cache:: 60 Obsolete for: index. 61 62working tree:: 63 The set of files and directories currently being worked on, 64 i.e. you can work in your working tree without using git at all. 65 66directory:: 67 The list you get with "ls" :-) 68 69revision:: 70 A particular state of files and directories which was stored in 71 the object database. It is referenced by a commit object. 72 73checkout:: 74 The action of updating the working tree to a revision which was 75 stored in the object database. 76 77commit:: 78 As a verb: The action of storing the current state of the index in the 79 object database. The result is a revision. 80 As a noun: Short hand for commit object. 81 82commit object:: 83 An object which contains the information about a particular 84 revision, such as parents, committer, author, date and the 85 tree object which corresponds to the top directory of the 86 stored revision. 87 88parent:: 89 A commit object contains a (possibly empty) list of the logical 90 predecessor(s) in the line of development, i.e. its parents. 91 92changeset:: 93 BitKeeper/cvsps speak for "commit". Since git does not store 94 changes, but states, it really does not make sense to use 95 the term "changesets" with git. 96 97clean:: 98 A working tree is clean, if it corresponds to the revision 99 referenced by the current head. 100 101dirty:: 102 A working tree is said to be dirty if it contains modifications 103 which have not been committed to the current branch. 104 105head:: 106 The top of a branch. It contains a ref to the corresponding 107 commit object. 108 109branch:: 110 A non-cyclical graph of revisions, i.e. the complete history of 111 a particular revision, which is called the branch head. The 112 branch heads are stored in `$GIT_DIR/refs/heads/`. 113 114master:: 115 The default branch. Whenever you create a git repository, a branch 116 named "master" is created, and becomes the active branch. In most 117 cases, this contains the local development. 118 119origin:: 120 The default upstream branch. Most projects have one upstream 121 project which they track, and by default 'origin' is used for 122 that purpose. New updates from upstream will be fetched into 123 this branch; you should never commit to it yourself. 124 125ref:: 126 A 40-byte hex representation of a SHA1 pointing to a particular 127 object. These may be stored in `$GIT_DIR/refs/`. 128 129head ref:: 130 A ref pointing to a head. Often, this is abbreviated to "head". 131 Head refs are stored in `$GIT_DIR/refs/heads/`. 132 133tree-ish:: 134 A ref pointing to either a commit object, a tree object, or a 135 tag object pointing to a tag or commit or tree object. 136 137ent:: 138 Favorite synonym to "tree-ish" by some total geeks. See 139 `http://en.wikipedia.org/wiki/Ent_(Middle-earth)` for an in-depth 140 explanation. 141 142tag object:: 143 An object containing a ref pointing to another object, which can 144 contain a message just like a commit object. It can also 145 contain a (PGP) signature, in which case it is called a "signed 146 tag object". 147 148tag:: 149 A ref pointing to a tag or commit object. In contrast to a head, 150 a tag is not changed by a commit. Tags (not tag objects) are 151 stored in `$GIT_DIR/refs/tags/`. A git tag has nothing to do with 152 a Lisp tag (which is called object type in git's context). 153 A tag is most typically used to mark a particular point in the 154 commit ancestry chain. 155 156merge:: 157 To merge branches means to try to accumulate the changes since a 158 common ancestor and apply them to the first branch. An automatic 159 merge uses heuristics to accomplish that. Evidently, an automatic 160 merge can fail. 161 162octopus:: 163 To merge more than two branches. Also denotes an intelligent 164 predator. 165 166resolve:: 167 The action of fixing up manually what a failed automatic merge 168 left behind. 169 170rewind:: 171 To throw away part of the development, i.e. to assign the head to 172 an earlier revision. 173 174rebase:: 175 To clean a branch by starting from the head of the main line of 176 development ("master"), and reapply the (possibly cherry-picked) 177 changes from that branch. 178 179repository:: 180 A collection of refs together with an object database containing 181 all objects, which are reachable from the refs, possibly accompanied 182 by meta data from one or more porcelains. A repository can 183 share an object database with other repositories. 184 185git archive:: 186 Synonym for repository (for arch people). 187 188file system:: 189 Linus Torvalds originally designed git to be a user space file 190 system, i.e. the infrastructure to hold files and directories. 191 That ensured the efficiency and speed of git. 192 193alternate object database:: 194 Via the alternates mechanism, a repository can inherit part of its 195 object database from another object database, which is called 196 "alternate". 197 198reachable:: 199 An object is reachable from a ref/commit/tree/tag, if there is a 200 chain leading from the latter to the former. 201 202chain:: 203 A list of objects, where each object in the list contains a 204 reference to its successor (for example, the successor of a commit 205 could be one of its parents). 206 207fetch:: 208 Fetching a branch means to get the branch's head ref from a 209 remote repository, to find out which objects are missing from 210 the local object database, and to get them, too. 211 212pull:: 213 Pulling a branch means to fetch it and merge it. 214 215push:: 216 Pushing a branch means to get the branch's head ref from a remote 217 repository, find out if it is an ancestor to the branch's local 218 head ref is a direct, and in that case, putting all objects, which 219 are reachable from the local head ref, and which are missing from 220 the remote repository, into the remote object database, and updating 221 the remote head ref. If the remote head is not an ancestor to the 222 local head, the push fails. 223 224pack:: 225 A set of objects which have been compressed into one file (to save 226 space or to transmit them efficiently). 227 228pack index:: 229 The list of identifiers, and other information, of the objects in a 230 pack, to assist in efficiently accessing the contents of a pack. 231 232core git:: 233 Fundamental data structures and utilities of git. Exposes only 234 limited source code management tools. 235 236plumbing:: 237 Cute name for core git. 238 239porcelain:: 240 Cute name for programs and program suites depending on core git, 241 presenting a high level access to core git. Porcelains expose 242 more of a SCM interface than the plumbing. 243 244object type: 245 One of the identifiers "commit","tree","tag" and "blob" describing 246 the type of an object. 247 248SCM:: 249 Source code management (tool). 250 251dircache:: 252 You are *waaaaay* behind. 253