I am currently doing a math problem and have come across an unfamiliar notation. A mini circle between $f$ and $h(x)$
The question ask me to find for 'the functions $f(x)=2x-1$ and $h(x)=3x+2$'
$$f \circ h(x)$$
However, I can't do this as I do not know what the circle notation denotes to. Does it mean to multiply?