Step 17 of 18 of the SMILES tutorial. Everything you have seen fits together in one string. Read CC(=O)Oc1ccccc1C(=O)O from the left: a methyl, a carbonyl carbon carrying its double bond oxygen in a branch, an ester oxygen, then a benzene ring opened with c1, and finally — on the ring atom that closes the ring — a carboxylic acid. That is aspirin, acetylsalicylic acid, and the two substituents come out ortho because the opening and closing ring atoms are neighbours. Rewrite it starting from the acid, OC(=O)c1ccccc1OC(C)=O, and confirm you drew the same molecule.
It opens on CC(=O)Oc1ccccc1C(=O)O, 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.