|= Patch Sets
|As described in link:concept-changes.html[Changes], a change represents a single
|commit under review. Each change is assigned a
|It is very common to amend a commit during the code review process. Gerrit uses
|the Change-Id to associate each iteration of the commit with the same change.
|These iterations of a commit are referred to as _patch sets_. When a change is
|approved, only the latest version of a commit is submitted to the repository.
|NOTE: It is also possible to copy a Change-Id to a completely new commit. This
|is useful in situations where you want to keep the discussion around a change,
|but also need to completely modify your approach.
|== File List
|When you open a change in Gerrit, a list of affected files appears in the
|file list, located in the middle of the Review screen. This table displays
|the following information for each file:
|* A checkbox, indicating the file has been reviewed
|* The type of modification
|* The path and name of the file
|* The number of added lines and or deleted lines
|== File modifications
|Each file in a patch set has a letter next to it, indicating the type of
|modification for that file. The following table lists the types of
|.Types of file modifications
||The file existed before this change and is modified.
||The file is newly added.
||The file is deleted.
||The file is renamed.
||The file is new and is copied from an existing file.
|If the status is *R* (Renamed) or *C* (Copied), the file list also displays the
|original name of the file below the patch set file.
|By default, Gerrit displays the latest patch set for a given change. You can
|view previous versions of a patch set by selecting from the *Patch Set*
|Clicking a file in the file list opens the Diff screen. By default, this
|screen displays a diff between the latest patch set's version of a file and the
|current version of that file in the repository. You can also open a diff within
|the Review screen by clicking the blue triangle located in the same row as the
|file. To show the diffs of all files in the Review screen, click the *Show
|Diffs* link, located at the top of the file list.
|You can diff between other patch sets by selecting a patch set number from the
|*Diff Against* drop-down list.
|Each change in Gerrit must have a change description. This change description
|comes from the commit message and becomes part of the history of the project.
|In addition to the change description, you can add a description for a specific
|patch set. This description is intended to help guide reviewers as a change
|evolves, such as "Added more unit tests." Unlike the change description, a patch
|set description does not become a part of the project's history.
|To add a patch set description, click *Add a patch set description*, located in
|the file list, or provide it link:user-upload.html#patch_set_description[on upload].
|Part of link:index.html[Gerrit Code Review]