when does the file conflict on svn

When does the file conflict on svn?
If more than one person are changed the same line of particular file for same version, and one of them do commit that new version on svn and other will do update new version for commit then there will be conflict in file.

with example
The same version of project available for everyone, suppose version 5 is available for suman and sanjeev now suppose sanjeev changed line number 8 and 9 of file index.php, and commit that version on svn, now on svn the new version has been made which is 6, now suman also change line number 8 on index.php, now suman try to update new version from svn which is 6, in that time there will be conflict because suman change the same line(code) for version 6, which is already changed by sanjeev..

if suman will change the same line after update new version 6, there will be no conflict because in that time suman will be changing that line for version 7 not for 6 so there will not be any conflict on file.