Mystical Tutor what is "mana source" and "interrupt" magic?

[vacation]

bought a bunch of older cards today and one of them mystical tutor says you can search for instant, interrupt, mana source or sorcery?

What is interrupt? is it old word for counterspells?

and mana source does it mean land only or also any card that makes mana like llanowar elves?

[Arix]

Interrupts and mana sources are old card types that no longer exist. All cards that used to have that type are now instants. Mystical Tutor can only fetch instants or sorceries.