In standard logic there are two laws that have to be followed. The Law of the Excluded Middle asserts that the statement has to be either true or false. While the Law of Non Contradiction states that no statement can both be true and false. With these laws, standard logic can break down any problem into individual statements that are either true or false. These statements can then be identified as either a premises or a conclusion that can become the evidence for a given argument. This evidence, depending on it's inter relational complexity can then be used to formally diagram the problem and solve whether the argument is either true or false. Knowing how to find what is true and false with this structured process allows us to solve any problem that we might face.
So how do you describe a statement that can pass the assumptions of standard logic? First you have to be able to identify it as a statement and not something else. The two possibilities that would not make it a statement are sentences and propositions. A sentence can have different sets that mean the same thing and it can contain more than one proposition or statement. In either case it would fail both of the standard logic assumptions and therefore could not be a statement. A proposition is much closer to a statement. It concerns itself with meaning and is not based on words. It however contains no context and therefore would also fail the assumption of Non Contradiction. What makes a statement different from both of these? In a word, context. With context you can take a proposition and make it specific enough to pass the law of Non Contradiction since it can only mean one thing which is either true or false. So you might ask why is this distinction important? Determining statements to be either true or false is the only way to break down a problem into small enough pieces so that you can develop a framework to find a certain truth within several pieces of evidence.