Coordinating conjunctions connect two main clauses of equal grammatical status without affecting the word order of either. The main ones are: en (and), maar (but), of (or), want (because — giving a reason), dus (so or therefore) and nog (nor). After want the normal main clause order continues: Hij bleef thuis, want hij was ziek. The V2 rule applies in both clauses independently.
Subordinating conjunctions introduce a dependent clause and require the finite verb to move to the end: omdat (because), dat (that), als (if or when), hoewel (although), terwijl (while), totdat (until), zodat (so that), voordat (before), nadat (after). Ik blijf thuis omdat ik ziek ben. Note that because in English is always subordinating, but Dutch want is coordinating and omdat is subordinating. Students frequently confuse them.
The distinction matters critically for word order. After want, the following clause keeps main clause order. After omdat, the verb moves to the end. This is the most common word-order error Dutch learners make: Ik bleef thuis want ik was moe is correct, while Ik bleef thuis omdat ik moe was is also correct with the verb at the end. If you start a sentence with a subordinating conjunction, the main clause follows with inversion: Omdat ik moe was, bleef ik thuis.