Step 9 of 18 of the SMILES tutorial. Branches work on ring atoms exactly as they do on chains. Cc1ccc(O)cc1 starts with a methyl, walks around the aromatic ring, and hangs an OH on the fourth ring atom, giving para-cresol. Ring atoms are visited in writing order, so where a branch sits in the string is where the substituent sits on the ring. Move the (O) one atom earlier — Cc1cc(O)ccc1 — and you have the meta isomer instead.
It opens on Cc1ccc(O)cc1, 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.