What is logical consequence and logically equivalent in discrete math?

Question

I'm having a difficult time understanding what the meaning are with these two.

Is it correct if I have (P ⇒ Q) ∧ P and I say Q is a logical consequence. This means that whatever P may be T or F the result all comes down to what Q is?

Answer 1

Logical consequence means :

"every time the premise ($(P → Q) ∧ P$) is TRUE, also the conclusion ($Q$) is TRUE."

Logical equivalence means that the two formulas have the same truth value in every model.

$Q$ is a logical consequence of $(P → Q) ∧ P$ but the two are not logically equivalent.

An example of two logically equivalent formulas is : $(P → Q)$ and $(¬P ∨ Q)$. We can use a truth table to check it.

For details, see Logical consequence :

"is a fundamental concept in logic, which describes the relationship between statements that hold true when one statement logically follows from one or more statements. A valid logical argument is one in which the conclusion is the consequence of the premises."

A premise is a statement that an argument claims will induce or justify a conclusion. In other words, a premise is an assumption that something is true.

A conclusion is the statement justified (in mathematics and logic : proved) by the premises of the argument.

Answer 2

Welcome to MSE.

You refer to the modus ponens, a logical rule. Semantically, it says that if $P$ is true and $P\Rightarrow Q$ is true, then $Q$ is true.

The rule is also (equivalently) applied in proofs (syntax). If you can write down $P$ and $P\Rightarrow Q$ starting from the axioms and the hypothetical propositions, then you can write down $Q$.