Read the following passage :
A rickshaw puller is a poor man and he lives in the slum. He toils very hard but he earns a little, he has to maintain a large family, yet he is happy.
In the first sentence, the two clauses (i) A rickshaw puller is a poor man and (ii) he lives in the slum are of the same nature and they are joined by coordinating conjunction and. So: the sentence A rickshaw puller is a poor man and he lives in the slum is a co-ordinate clause. Similarly, the other clauses in the passage are co-ordinated clauses.
When two clauses of the same nature are joined by coordinating conjunction is called a co-ordinate clause.
N. B. Co-ordinating conjunctions: and, both - and, also, too, as well as, no less than, not only but also, now, well, either —or, neither — nor, otherwise, else, or, but, still, yet, nevertheless, however, whereas, while, only, therefore, then, so, so then.