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 fast forward::
72 A fast-forward is a special type of merge where you have
73 a revision and you are "merging" another branch's changes
74 that happen to be a descendant of what you have.
75 In such these cases, you do not make a new merge commit but
76 instead just update to his revision. This will happen
77 frequently on a tracking branch of a remote repository.
79 fetch::
80 Fetching a branch means to get the branch's head ref from a
81 remote repository, to find out which objects are missing from
82 the local object database, and to get them, too.
84 file system::
85 Linus Torvalds originally designed git to be a user space file
86 system, i.e. the infrastructure to hold files and directories.
87 That ensured the efficiency and speed of git.
89 git archive::
90 Synonym for repository (for arch people).
92 hash::
93 In git's context, synonym to object name.
95 head::
96 The top of a branch. It contains a ref to the corresponding
97 commit object.
99 head ref::
100 A ref pointing to a head. Often, this is abbreviated to "head".
101 Head refs are stored in `$GIT_DIR/refs/heads/`.
103 index::
104 A collection of files with stat information, whose contents are
105 stored as objects. The index is a stored version of your working
106 tree. Truth be told, it can also contain a second, and even a third
107 version of a working tree, which are used when merging.
109 index entry::
110 The information regarding a particular file, stored in the index.
111 An index entry can be unmerged, if a merge was started, but not
112 yet finished (i.e. if the index contains multiple versions of
113 that file).
115 master::
116 The default branch. Whenever you create a git repository, a branch
117 named "master" is created, and becomes the active branch. In most
118 cases, this contains the local development.
121 merge::
122 To merge branches means to try to accumulate the changes since a
123 common ancestor and apply them to the first branch. An automatic
124 merge uses heuristics to accomplish that. Evidently, an automatic
125 merge can fail.
127 object::
128 The unit of storage in git. It is uniquely identified by
129 the SHA1 of its contents. Consequently, an object can not
130 be changed.
132 object database::
133 Stores a set of "objects", and an individual object is identified
134 by its object name. The objects usually live in `$GIT_DIR/objects/`.
136 object identifier::
137 Synonym for object name.
139 object name::
140 The unique identifier of an object. The hash of the object's contents
141 using the Secure Hash Algorithm 1 and usually represented by the 40
142 character hexadecimal encoding of the hash of the object (possibly
143 followed by a white space).
145 object type:
146 One of the identifiers "commit","tree","tag" and "blob" describing
147 the type of an object.
149 octopus::
150 To merge more than two branches. Also denotes an intelligent
151 predator.
153 origin::
154 The default upstream branch. Most projects have one upstream
155 project which they track, and by default 'origin' is used for
156 that purpose. New updates from upstream will be fetched into
157 this branch; you should never commit to it yourself.
159 pack::
160 A set of objects which have been compressed into one file (to save
161 space or to transmit them efficiently).
163 pack index::
164 The list of identifiers, and other information, of the objects in a
165 pack, to assist in efficiently accessing the contents of a pack.
167 parent::
168 A commit object contains a (possibly empty) list of the logical
169 predecessor(s) in the line of development, i.e. its parents.
171 pickaxe:: The term pickaxe refers to an option to the diffcore routines
172 that help select changes that add or delete a given text string.
173 With the --pickaxe-all option, it can be used to view the
174 full changeset that introduced or removed, say, a particular
175 line of text. See gitlink:git-diff[1].
177 plumbing::
178 Cute name for core git.
180 porcelain::
181 Cute name for programs and program suites depending on core git,
182 presenting a high level access to core git. Porcelains expose
183 more of a SCM interface than the plumbing.
185 pull::
186 Pulling a branch means to fetch it and merge it.
188 push::
189 Pushing a branch means to get the branch's head ref from a remote
190 repository, find out if it is an ancestor to the branch's local
191 head ref is a direct, and in that case, putting all objects, which
192 are reachable from the local head ref, and which are missing from
193 the remote repository, into the remote object database, and updating
194 the remote head ref. If the remote head is not an ancestor to the
195 local head, the push fails.
197 reachable::
198 An object is reachable from a ref/commit/tree/tag, if there is a
199 chain leading from the latter to the former.
201 rebase::
202 To clean a branch by starting from the head of the main line of
203 development ("master"), and reapply the (possibly cherry-picked)
204 changes from that branch.
206 ref::
207 A 40-byte hex representation of a SHA1 pointing to a particular
208 object. These may be stored in `$GIT_DIR/refs/`.
210 refspec::
211 A refspec is used by fetch and push to describe the mapping
212 between remote ref and local ref. They are combined with
213 a colon in the format <src>:<dst>, preceded by an optional
214 plus sign, +. For example:
215 `git fetch $URL refs/heads/master:refs/heads/origin`
216 means "grab the master branch head from the $URL and store
217 it as my origin branch head".
218 And `git push $URL refs/heads/master:refs/heads/to-upstream`
219 means "publish my master branch head as to-upstream master head
220 at $URL". See also gitlink:git-push[1]
222 repository::
223 A collection of refs together with an object database containing
224 all objects, which are reachable from the refs, possibly accompanied
225 by meta data from one or more porcelains. A repository can
226 share an object database with other repositories.
228 resolve::
229 The action of fixing up manually what a failed automatic merge
230 left behind.
232 revision::
233 A particular state of files and directories which was stored in
234 the object database. It is referenced by a commit object.
236 rewind::
237 To throw away part of the development, i.e. to assign the head to
238 an earlier revision.
240 SCM::
241 Source code management (tool).
243 SHA1::
244 Synonym for object name.
246 tracking branch::
247 A regular git branch that is used to follow changes from
248 another repository. A tracking branch should not contain
249 direct modifications or made commits made locally.
250 A tracking branch can usually be identified as the
251 right-hand-side ref in a Pull: refspec.
253 tree object::
254 An object containing a list of file names and modes along with refs
255 to the associated blob and/or tree objects. A tree is equivalent
256 to a directory.
258 tree::
259 Either a working tree, or a tree object together with the
260 dependent blob and tree objects (i.e. a stored representation
261 of a working tree).
263 tree-ish::
264 A ref pointing to either a commit object, a tree object, or a
265 tag object pointing to a tag or commit or tree object.
267 tag object::
268 An object containing a ref pointing to another object, which can
269 contain a message just like a commit object. It can also
270 contain a (PGP) signature, in which case it is called a "signed
271 tag object".
273 tag::
274 A ref pointing to a tag or commit object. In contrast to a head,
275 a tag is not changed by a commit. Tags (not tag objects) are
276 stored in `$GIT_DIR/refs/tags/`. A git tag has nothing to do with
277 a Lisp tag (which is called object type in git's context).
278 A tag is most typically used to mark a particular point in the
279 commit ancestry chain.
281 unmerged index:
282 An index which contains unmerged index entries.
284 working tree::
285 The set of files and directories currently being worked on,
286 i.e. you can work in your working tree without using git at all.