i'll never get why people always have all those unnecessary lines and circles all over their drafts
all it does is take up space and clutter the whole thing
not really
Block-in is where you just draw in basic shapes and then add details and almost "sculpt" them into the shape you want. So like with this wolf guy I'd draw a circle to represent the round head, a box for the snout and then two triangles for ears. Then I make a sketch on top of that and start getting the exact shapes down. Plus, especially in this sketch, it's a good idea to sometimes draw in stuff you won't be able to see but would affect something else. Like the head and helmet, you won't be seeing the top of his head but it's useful when drawing the helmet so that I can determine how thick it is. Also with the ears so I can get the placement and length right even with all the other crap hiding 2/3 of it
another thing you might see in that sketch is a bit of simple measuring as you can see from a couple faint lines down from the top of the visor to his snout, it's to remind me how the distances and proportions relate and helps you understand the shape even more