Help with sculping a character

Whenever I’m watching old tutorials for Blender 2.7 about creating a character , they always seem to do something that I can’t yet figure it out how they do it.
Usually when they go near the neck they start adding more shapes which they sometimes add a smooth modifier (all good so far) and then I don’t know what happens… Is it a separate layer (group) does it really matter what I do if I want to start adding bones after the sculping ? I’m so sorry if this sounds so basic but I really need help out here. Ty so much

Can you link to one of these tutorials?