CVS marks conflicts with in-line “conflict markers”, and prints a C during an update. Historically, this has caused problems, because CVS isn't doing enough. Many users forget about (or don't see) the C after it whizzes by on their terminal. They often forget that the conflict-markers are even present, and then accidentally commit files containing conflict-markers.

Subversion solves this problem by making conflicts more tangible. It remembers that a file is in a state of conflict, and won't allow you to commit your changes until you run svn resolved. See the section called “Resolve Conflicts (Merging Others' Changes)” for more details.