In English and in German, conjunctions are used to combine two clauses together. There are independent (main) and dependent (subordinate) clauses. Independent clauses are sentences that can stand alone and still make perfect sense (hence: "independent). We can combine two independent clauses using a coordinating conjunction (koordinierende Konjunktion), which does not alter the word order of the joined clauses.
Ich spiele Basketball. Er spielt Fussball. (I play basketball. He plays soccer.)
These are two main/independent clauses. I can combine the two by using a coordinating conjunction. I can, for example, use "und" (and)
Ich spiele Basketball und er spielt Fussball. (I play basketball and he plays soccer.
Notice how the word order remained the same in both main clauses, even after they were joined together with "und".
The coordinating conjunctions are:
When the subject (and the verb) are the same in both clauses, often we can abbreviate the second main clause.
Er spielt nicht Gitarre, sondern (er spielt) Bass. -> Subject and verb are the same
Ich putze das Badezimmer, und (ich) mache Hausaufgaben. -> Subject is the same
When an independent clause is combined with a dependent clauses (a clause that cannot stand alone, and "depends" on the main clause) we need to use subordinating conjunctions (subordinierende / unterordnende Konjunktion). These conjunctions change the word order of the dependent clauses they appear in by shifting the conjugated (finite) verb to the end of the clause (not necessarily the end of the whole sentence.