English there are five forms of sentences:
simple: one independent clause--
The children are playing outdoors.
compound: two or more independent clauses--
The children are playing outdoors, and their parents are playing Scrabble indoors.
complex: one independent clause and one or more dependent clauses--
The children are playing outdoors while their parents are playing Scrabble indoors.
compound-complex: two or more independent clauses and one or more dependent clauses--
The children are playing outdoors because the weather is nice, but their
parents are playing Scrabble indoors.
complex-complex: one or more independent clauses and at least one dependent clause which
contains an imbedded dependent clause--
The children, who are playing outdoors because the weather is nice, are
happy.