It has at least two things, a subject and a verb. It can contain one word, or many words. Alright, now you're confused. This is where I segue into an explanation of the different types of sentences. Here we go.
Statements are exactly that.
They state something. They give information. In fact, every sentence in this definintion of a statement is a statement. Statements may be true or false, right or wrong. They always end with a period.