Clause:
A clause is a part of a sentence. There are two main types: independent (main clauses), dependent (subordinate clauses).

Clauses can perform three distinct functions. They can operate as:

Noun clause: She completely understood everything he said.
Adjective clause: My friend who rides a motorcycle said it’s a great weekend to ride.
Adverb clause: She fixed the sink without facing difficulty.

Types of clauses:

Independent clauses
A clause in a complex sentence that can stand alone as a complete sentence.
In other words,
An independent clause is a clause that can stand on its own as a distinct sentence.
Examples:
- I love eating cookies.
- My dog barks a lot.

Dependent clause.
It needs an independent clause to finish or complete the sentence.
Ex. When I got home, I ate dinner.
Dependent clauses are sometimes known as subordinate clauses. Example: When I grow up
To turn these dependent clauses into full sentences, you need to combine them with independent clauses: এরা নিজের অর্থ নিজে প্রকাশ করতে পারেনা, এদের অপর একটি Independent clause এর সাহায্যের প্রয়োজন হয়।
Keep in mind that, Whenever the dependent clause comes first in a complex sentence, it’s followed by a comma.

Kinds of Dependent clause:

Dependent or subordinate clauses can be divided again into 3 categories:

1. Adverb clause
2. Adjective clause
3. Noun clause.

Source: English Grammar in use by Raymond Murphy & A passage to the English Language by S.M Zakir Hussain