Step 3 of 18 of the SMILES tutorial. A branch in parentheses hangs off the atom written immediately before it, and the chain resumes from that same atom once the parenthesis closes. In CC(C)CO the second carbon carries a methyl group, which makes isobutanol. One atom may carry several branches — CC(C)(C)C is neopentane — and branches nest inside branches. Delete the parentheses and the molecule straightens out into butan-1-ol.
It opens on CC(C)CO, which you can edit in place: the structure follows every keystroke, and so does the notation when you draw instead.
Convert between chemical structures and SMILES in both directions, search a list of structures by substructure or SMARTS, and learn the notation step by step. Everything runs in your browser — no structure you open ever leaves your machine — so the tool needs JavaScript.