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 individial object is identified 23 by its object name. The object 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 cache 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 cache 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 cache 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 114ref:: 115 A 40-byte hex representation of a SHA1 pointing to a particular 116 object. These may be stored in $GIT_DIR/refs/. 117 118head ref:: 119 A ref pointing to a head. Often, this is abbreviated to "head". 120 Head refs are stored in $GIT_DIR/refs/heads/. 121 122tree-ish:: 123 A ref pointing to either a commit object, a tree object, or a 124 tag object pointing to a tag or commit or tree object. 125 126ent:: 127 Favorite synonym to "tree-ish" by some total geeks. See 128 http://en.wikipedia.org/wiki/Ent_(Middle-earth) for an in-depth 129 explanation. 130 131tag object:: 132 An object containing a ref pointing to another object, which can 133 contain a message just like a commit object. It can also 134 contain a (PGP) signature, in which case it is called a "signed 135 tag object". 136 137tag:: 138 A ref pointing to a tag or commit object. In contrast to a head, 139 a tag is not changed by a commit. Tags (not tag objects) are 140 stored in $GIT_DIR/refs/tags/. A git tag has nothing to do with 141 a Lisp tag (which is called object type in git's context). 142 A tag is most typically used to mark a particular point in the 143 commit ancestry chain. 144 145merge:: 146 To merge branches means to try to accumulate the changes since a 147 common ancestor and apply them to the first branch. An automatic 148 merge uses heuristics to accomplish that. Evidently, an automatic 149 merge can fail. 150 151octopus:: 152 To merge more than two branches. Also denotes an intelligent 153 predator. 154 155resolve:: 156 The action of fixing up manually what a failed automatic merge 157 left behind. 158 159rewind:: 160 To throw away part of the development, i.e. to assign the head to 161 an earlier revision. 162 163rebase:: 164 To clean a branch by starting from the head of the main line of 165 development ("master"), and reapply the (possibly cherry-picked) 166 changes from that branch. 167 168repository:: 169 A collection of refs together with an object database containing 170 all objects, which are reachable from the refs, possibly accompanied 171 by meta data from one or more porcelains. A repository can 172 share an object database with other repositories. 173 174git archive:: 175 Synonym for repository (for arch people). 176 177file system:: 178 Linus Torvalds originally designed git to be a user space file 179 system, i.e. the infrastructure to hold files and directories. 180 That ensured the efficiency and speed of git. 181 182alternate object database:: 183 Via the alternates mechanism, a repository can inherit part of its 184 object database from another object database, which is called 185 "alternate". 186 187reachable:: 188 An object is reachable from a ref/commit/tree/tag, if there is a 189 chain leading from the latter to the former. 190 191chain:: 192 A list of objects, where each object in the list contains a 193 reference to its successor (for example, the successor of a commit 194 could be one of its parents). 195 196fetch:: 197 Fetching a branch means to get the branch's head ref from a 198 remote repository, to find out which objects are missing from 199 the local object database, and to get them, too. 200 201pull:: 202 Pulling a branch means to fetch it and merge it. 203 204push:: 205 Pushing a branch means to get the branch's head ref from a remote 206 repository, find out if it is an ancestor to the branch's local 207 head ref is a direct, and in that case, putting all objects, which 208 are reachable from the local head ref, and which are missing from 209 the remote repository, into the remote object database, and updating 210 the remote head ref. If the remote head is not an ancestor to the 211 local head, the push fails. 212 213pack:: 214 A set of objects which have been compressed into one file (to save 215 space or to transmit them efficiently). 216 217pack index:: 218 The list of identifiers, and other information, of the objects in a 219 pack, to assist in efficiently accessing the contents of a pack. 220 221core git:: 222 Fundamental data structures and utilities of git. Exposes only 223 limited source code management tools. 224 225plumbing:: 226 Cute name for core git. 227 228porcelain:: 229 Cute name for programs and program suites depending on core git, 230 presenting a high level access to core git. Porcelains expose 231 more of a SCM interface than the plumbing. 232 233object type: 234 One of the identifiers "commit","tree","tag" and "blob" describing 235 the type of an object. 236 237SCM:: 238 Source code management (tool). 239 240dircache:: 241 You are *waaaaay* behind. 242