Here is a binding video that takes a humorous look at thermal binding machines vs. comb binding machines. Of course, it slightly exaggerates the comb binding process and leaves out the benefits of comb binding (such as easily editing documents). But you get the idea.
Thermal binding is a 1-step process that doesn’t require punching or dealing with separate covers and spines. Comb binding does require punching and uses a separate spine. Each style has it’s place … compare binding styles now.