[Math] Difference between f(x) and f(x,y)

Question

I recently started doing calculus and came across terms such as f(x) and f(x,y). What is the difference between them? Are they the same thing?

Answer 1

$f(x)$ is a function of a single variable. For example, $f(x)=x^2$

$f(x,y)$ is a function of two variables. For example, $f(x)=x^2y+xy$.