1. Let's start by understanding what a function is. A function is a rule that assigns each input exactly one output. For example, if you have a function $f(x) = x^2$, it means for every number $x$ you put in, you get $x$ squared as the output. 2. The domain of a function is the set of all possible inputs. For $f(x) = x^2$, the domain is all real numbers because you can square any real number. 3. The image set (or range) is the set of all possible outputs. For $f(x) = x^2$, the image set is all real numbers greater than or equal to zero, because squaring any real number cannot give a negative result. 4. Now, about the symbol $A \lor B$, this is a logical statement meaning "A or B". It is true if at least one of $A$ or $B$ is true. 5. To summarize, functions relate inputs to outputs, domains are the inputs you can use, image sets are the outputs you get, and logical statements like $A \lor B$ describe conditions that can be true or false.