Whether is a subordinating conjunction, meaning that it is used to connect a dependent clause to an independent clause. It is mostly accompanied by another subordinating conjunction 'or'.
Subordinating Conjunctions
Subordinating conjunctions joins subordinate or dependent clauses to the main or independent clauses. To know all about these tricky grammatical words, click!
'Whether' can be accompanied with 'or not.' In this case there is a small distinction between 'whether' and 'whether or not' which we will learn in this lesson.