until vs as long as

[confuse mind]

what is the difference in the usages of until and 'as long as'
are both correct?


I will play as long as it does not rain.
I will play until it rains.

[Kasia@EconomistGMAT]

The meaning of both sentences is very similar and both are correct.
"as long as" = during the time that...
"until" = up to the time that...