Active and passive items
Also called: active items, passive items, active item slots, Z X C V, usable items, item abilities, item actives, active item keybinds
Active items need a deliberate input; passive effects apply under their stated conditions. Some items include more than one kind of effect.
In practice
Know the assigned keys and cooldowns of your active items. For passive effects, check what triggers them rather than assuming they are always active.
Common questions
Can I activate every defensive item after being stunned?
No. Some explicitly cannot be used then and must be prepared before the control lands.
Does passive mean permanent unconditional benefit?
No. Many passive effects have triggers, cooldowns or target restrictions.