Nesting

Premiere calls it a nested sequence, Final Cut and Resolve both call it a compound clip. Whatever the name, you select a run of clips and collapse them into one block that behaves like a single piece of footage. It is how you apply one effect, speed change or grade to a whole section without repeating it 20 times, and how you keep a complicated intro from cluttering the main timeline. The cost is access: to change anything inside you have to open the nest, and heavily nested projects get hard to unpick months later. Nest late and nest shallow.