Instant
From MTG Salvation Wiki
Instants, like sorceries, represent one-shot or short-term magical spells. They are never put into the in-play zone; instead, they take effect when their mana cost is paid and the spell resolves, and then are immediately put into the player's graveyard.
Sorceries and instants differ only in when they can be played. Sorceries can only be played during the player's main phase, and only when nothing else is on the stack. Instants, on the other hand, can be played at any time, including during other player's turns and while another spell or ability is waiting to resolve. The term "spell" collectively refer to instants and sorceries.
From the Comprehensive Rules:
|
| Card types | ||||
|---|---|---|---|---|
| Groups | Supertypes | Card types | Subtypes | |
| Spell (non-permanent) | Instant
| Trap | Arcane | |
Sorcery 
| ||||
| Permanent | Basic, Legendary, Snow, World | Artifact 
| Equipment, Fortification, Contraption | |
Creature 
| (...) | |||
Enchantment 
| Aura, Shrine | |||
Land 
| (...) | |||
Planeswalker 
| (...) | |||
| Miscellaneous | Tribal | (...) | ||
| Plane | (...) | |||
| Vanguard | ||||
| Obsolete | Mono, Poly, Continuous | Interrupt, Mana Source | ||
