Definition:Statement

A statement is a sentence which has objective and logical meaning.

In a non-mathematical context, the term "statement" has a wider and looser meaning than this.

Equivalent terms for "statement" are:

Assertion;

Declarative sentence;

Declaration;

Expression (used in a wider context, and has a less precise interpretation).

The term proposition is often seen for "statement", but modern usage prefers to reserve the term "proposition" for something more specific.

In Aristotelian logic all statements have a truth value that is either true or false.

In multi-value logic, it is admissible for a statement to have a truth value other than those two values.

Simple and Compound
A statement may be either simple, consisting of just a subject and a predicate, or compound, which is a statement that consists of one or more simple statements joined together by logical connectives.

There are other sorts of sentences which may be encountered, for example:

Questions: for example: "What do you get if you multiply six by nine?"

Commands: for example: "Multiply six by nine."

Other types of sentence which are also technically "commands" are:

Instructions: "In order to solve this problem, you need to multiply six by nine."

Requests: "Would you please kindly multiply six by nine, if it's not too much trouble?"

"Why don't you just sit right down there and multiply six by nine?"

Exhortations: "May the powers that be strike me down here and now if six multiplied by nine isn't forty-two in base thirteen!"

In the field of computer science, where it is more usual to encounter "commands" and "questions", the term "statement" is generally used to encompass all types of "sentence"; what we refer to as a "statement" tends to be given the term "assertion".