Knowing that the clause is a group of words that contain mainly a subject and a tense , and it may be dependent or independent, what is the difference between the latter and a sentence.? This doubt is due to the fact that the author of a textbook, uses "a sentence" in the middle of explanations related to connectors after having been using "clauses" all the time, so I am in doubt whether he is referring to the same but with a different name.
To summarize AlanCarmack's explanation, an independent clause is a complete sentence joined to another clause or clauses, which themselves may be either dependent or independent.
Independent clauses, or coordinate clauses, are joined by coordinating conjunctions, which are and, but, or, for, nor, yet, and so. Dependent clauses, or subordinate clauses, are joined by subordinating conjunctions, some of which are after, although, as, because, before, how, if, since, though, until, when, where, and while. Clauses that begin with these can't function as sentences on their own; they have to be joined to another clause that can function as a sentence on its own.
Here's an example of each:
I went to the ball game yesterday, and I saw my friend Tim there.
I went to the ball game yesterday, where I saw my friend Tim.
Now, have a look at this:
I went to the ball game yesterday. I saw my friend Tim there.
I went to the ball game yesterday. Where I saw my friend Tim.
Of these sentences, "Where I saw my friend Tim." is incorrect, because it isn't a complete sentence. All the other sentences are correct.