This technology allows the writing process to be stopped and resumed at any point without compromising compatibility. Without lossless linking, this process would create empty space that would make the disc incompatible with many DVD players and DVD-ROM drives. Lossless linking also allows you to add, edit or replace data on your disc without having to erase it first.
All of the rewriteable DVD formats have lossless linking except DVD-RAM, which doesn't need it.