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 blob and/or tree objects. 30 (A tree usually corresponds to a directory without 31 subdirectories). 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 38index:: 39 A collection of files with stat information, whose contents are 40 stored as objects. The cache is a stored version of your working 41 tree. Truth be told, it can also contain a second, and even a third 42 version of a working tree, which are used when merging. 43 44index entry:: 45 The information regarding a particular file, stored in the index. 46 An index entry can be unmerged, if a merge was started, but not 47 yet finished (i.e. if the cache contains multiple versions of 48 that file). 49 50unmerged index: 51 An index which contains unmerged index entries. 52 53cache:: 54 Obsolete for: index. 55 56working tree:: 57 The set of files and directories currently being worked on, 58 i.e. you can work in your working tree without using git at all. 59 60directory:: 61 The list you get with "ls" :-) 62 63revision:: 64 A particular state of files and directories which was stored in 65 the object database. It is referenced by a commit object. 66 67checkout:: 68 The action of updating the working tree to a revision which was 69 stored in the object database. 70 71commit:: 72 As a verb: The action of storing the current state of the cache in the 73 object database. The result is a revision. 74 As a noun: Short hand for commit object. 75 76commit object:: 77 An object which contains the information about a particular 78 revision, such as parents, committer, author, date and the 79 tree object which corresponds to the top directory of the 80 stored revision. 81 82parent:: 83 A commit object contains a (possibly empty) list of the logical 84 predecessor(s) in the line of development, i.e. its parents. 85 86changeset:: 87 BitKeeper/cvsps speak for "commit". Since git does not store 88 changes, but states, it really does not make sense to use 89 the term "changesets" with git. 90 91clean:: 92 A working tree is clean, if it corresponds to the revision 93 referenced by the current head. 94 95dirty:: 96 A working tree is said to be dirty if it contains modifications 97 which have not been committed to the current branch. 98 99head:: 100 The top of a branch. It contains a ref to the corresponding 101 commit object. 102 103branch:: 104 A non-cyclical graph of revisions, i.e. the complete history of 105 a particular revision, which is called the branch head. The 106 branch heads are stored in $GIT_DIR/refs/heads/. 107 108ref:: 109 A 40-byte hex representation of a SHA1 pointing to a particular 110 object. These may be stored in $GIT_DIR/refs/. 111 112head ref:: 113 A ref pointing to a head. Often, this is abbreviated to "head". 114 Head refs are stored in $GIT_DIR/refs/heads/. 115 116tree-ish:: 117 A ref pointing to either a commit object, a tree object, or a 118 tag object pointing to a tag or commit or tree object. 119 120ent:: 121 Favorite synonym to "tree-ish" by some total geeks. 122 123tag object:: 124 An object containing a ref pointing to another object. It can 125 contain a (PGP) signature, in which case it is called "signed 126 tag object". 127 128tag:: 129 A ref pointing to a tag or commit object. In contrast to a head, 130 a tag is not changed by a commit. Tags (not tag objects) are 131 stored in $GIT_DIR/refs/tags/. A git tag has nothing to do with 132 a Lisp tag (which is called object type in git's context). 133 A tag is most typically used to mark a particular point in the 134 commit ancestry chain. 135 136merge:: 137 To merge branches means to try to accumulate the changes since a 138 common ancestor and apply them to the first branch. An automatic 139 merge uses heuristics to accomplish that. Evidently, an automatic 140 merge can fail. 141 142resolve:: 143 The action of fixing up manually what a failed automatic merge 144 left behind. 145 146repository:: 147 A collection of refs together with an object database containing 148 all objects, which are reachable from the refs, possibly accompanied 149 by meta data from one or more porcelains. A repository can 150 share an object database with other repositories. 151 152git archive:: 153 Synonym for repository (for arch people). 154 155file system:: 156 Linus Torvalds originally designed git to be a user space file 157 system, i.e. the infrastructure to hold files and directories. 158 That ensured the efficiency and speed of git. 159 160alternate object database:: 161 Via the alternates mechanism, a repository can inherit part of its 162 object database from another object database, which is called 163 "alternate". 164 165reachable:: 166 An object is reachable from a ref/commit/tree/tag, if there is a 167 chain leading from the latter to the former. 168 169chain:: 170 A list of objects, where each object in the list contains a 171 reference to its successor (for example, the successor of a commit 172 could be one of its parents). 173 174fetch:: 175 Fetching a branch means to get the branch's head ref from a 176 remote repository, to find out which objects are missing from 177 the local object database, and to get them, too. 178 179pull:: 180 Pulling a branch means to fetch it and merge it. 181 182push:: 183 Pushing a branch means to get the branch's head ref from a remote 184 repository, find out if it is an ancestor to the branch's local 185 head ref is a direct, and in that case, putting all objects, which 186 are reachable from the local head ref, and which are missing from 187 the remote repository, into the remote object database, and updating 188 the remote head ref. If the remote head is not an ancestor to the 189 local head, the push fails. 190 191pack:: 192 A set of objects which have been compressed into one file (to save 193 space or to transmit them efficiently). 194 195pack index:: 196 The list of identifiers, and other information, of the objects in a 197 pack, to assist in efficiently accessing the contents of a pack. 198 199plumbing:: 200 Cute name for core git. 201 202porcelain:: 203 Cute name for programs and program suites depending on core git, 204 presenting a high level access to core git. Porcelains expose 205 more of a SCM interface than the plumbing. 206 207object type: 208 One of the identifiers "commit","tree","tag" and "blob" describing 209 the type of an object. 210 211SCM:: 212 Source code management (tool). 213 214dircache:: 215 You are *waaaaay* behind. 216