A linear function is a mathematical function that can be represented by a straight line when graphed on a Cartesian coordinate system.

It is an algebraic expression of the form
f(x) = mx + b

Explanation: The given image shows the linear function, so here
f(x) represents the output or dependent variable.
x represents the input or independent variable and
m represents the slope of the line.
b represents the y-intercept (the point where the line crosses the y-axis).