Terms are separated by plus and minus signs, meaning 4b, 7b, and 5 are all separate terms.
Like terms are pretty self explanatory, and they are 4b and 7b, both multiples of b.
The coefficients can be thought of as the number that a variable is multiplied by, and the only variable we see here is b. The coefficients are 4 and 7.
The constant is 5; its value stays at 5, because its value doesn't depend on a variable (the value is constant).
