Activities
Source Player Core pg. 406
An activity typically involves using multiple actions to create an effect greater than you can produce with a single action, or combining multiple single actions to produce an effect that's different from merely the sum of those actions. In some cases, usually when spellcasting, an activity can consist of only 1 action, 1 reaction, or even 1 free action.
An activity might cause you to use specific actions within it. You don't have to spend additional actions to perform them—they're already factored into the activity's required actions. (See Subordinate Actions below.)
You have to spend all the actions of an activity at once to gain its effects. In an encounter, this means you must complete it during your turn. If an activity gets interrupted or disrupted in an encounter, you lose all the actions you committed to it.
An activity might cause you to use specific actions within it. You don't have to spend additional actions to perform them—they're already factored into the activity's required actions. (See Subordinate Actions below.)
You have to spend all the actions of an activity at once to gain its effects. In an encounter, this means you must complete it during your turn. If an activity gets interrupted or disrupted in an encounter, you lose all the actions you committed to it.
Exploration and Downtime Activities
Source Player Core pg. 406
Outside of encounters, activities can take minutes, hours, or even days. These activities usually have the exploration or downtime trait to indicate they're meant to be used during these modes of play. You can often do other things off and on as you carry out these activities, provided they aren't significant activities of their own. For instance, if you're Repairing an item, you might stretch your legs or have a brief discussion, but you couldn't Decipher Writing at the same time.
If an activity outside of an encounter is interrupted or disrupted, as described in Disrupting Actions, you usually lose the time you put in, but no additional time.
If an activity outside of an encounter is interrupted or disrupted, as described in Disrupting Actions, you usually lose the time you put in, but no additional time.