Until vs. Till

Until and till are two words which mean exactly the same thing. They can both be used as prepositions and conjunctions. These two words can be used interchangeably. They refer to a time frame and are used when someone is talking about something related to time.

Till is used in a more informal way.
E. g.

I will wait till I hear from you.

Until is a formal term compared to till.
E. g.

I usually work from 10 am until 6 pm.

Till and until are both separate words, till is not derived from until and it is incorrect to spell it as untill.
E. g.

It rained till (until) midnight.

Until and till both show time. They cannot be used to talk about distance. Instead we use 'to', 'as far as' or 'up to'.
We walked as far as the edge of the forest. (NOT We walked until the edge of the forest. )

To talk about quantity we can use 'up to'.
This car can seat up to eight people. (NOT This car can seat until eight people. )