What is the difference between a compound and complex sentence?

A compound sentence is a combination of two or more simple sentences. (A simple sentence expresses one complete thought.) These simple sentences are linked by a coordinating conjunction (and, but, or, for, yet, not, so), a semicolon, or a semicolon and a conjunctive adverb:

The weather was pleasant, but the wind kept us from sailing.

The costs are much too high; we'll have to look elsewhere.

The acoustics were poor; however, we could hear their voices. 

A complex sentence is the union of a simple sentence and a dependent or subordinate clause. (A dependent or subordinate clause cannot stand alone as a simple sentence.) The dependent or subordinate clause can appear before, in the middle of, or after the simple sentence:

Although the content was brief, the message was convincing.

Indirect people, who move at a slower pace, are very cautious.

Adaptability is difficult because we tend to be very egocentric.