Can you explain what the mappings do? I usually use the asterisk to search for the token under the cursor, edit the sought token using cw and then n.n.n.n. to

Can you explain what the mappings do? I usually use the asterisk to search for the token under the cursor, edit the sought token using cw and then n.n.n.n. to replace later occurrences. I don't see how the mapping makes this more efficient.