Selection identifies an item
Click a timeline clip to inspect or edit it. The inspector follows the selected item. The playhead controls which time you see; moving it does not always select the clip under it.
Use the Selection tool (A) for normal selection. The Blade tool (B) has a different purpose: clicking a clip splits it.
Targeting identifies a destination
Source patching controls how incoming source components map into the sequence. Edit Targets controls which tracks a timeline command acts on. These settings are separate, so a visible selection does not establish every command destination.
Review track labels and target indicators before a multi-track operation. Lock a track when it should be protected from edits, and check that lock state when an operation is unavailable.
Avoid focus surprises
Text fields keep normal typing and local Undo behavior. Click the intended editing surface before using single-key editing shortcuts. Use command search to read a command’s current availability rather than guessing why a key had no effect.