PQR - What is the meaning of this common code?

[Sheriffs]

It's a code that i saw in many profiles, but idk what is the meaning...

So... What is "select(#", for example: 7 and 4.

select(7,UnitBuffID("player", XXX)) - GetTime()

or

select(4,UnitBuffID("player", XXX))

I do know what UnitBuffID is, but not this "select and number" thing. Please, help.

Tyvm.

[kuukuu]

Select and the number is used to select which return you want to look at instead of typing out every single one. For example, select (4, UnitBuffID("player, XXX)) would check the expiration of the buff if I remember correctly.

[Quesadilla]

1=name, 2=rank, 3=icon, 4=count, 5=debuffType, 6=duration, 7=expirationTime, 8=unitCaster, 9=isStealable