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