Therapeutics is the branch of medicine concerned with treatment — not with naming a disease or explaining its causes, but with what you actually do about it: which drug, which dose, which procedure, and whether it works. A medical student studies anatomy to learn how the body is built, pathology to learn how it goes wrong, and therapeutics to learn how to put it right. Two things to notice about the grammar. First, it ends in -s but behaves as one thing: 'therapeutics is a difficult subject', like 'physics is', 'mathematics is', 'economics is'. Second, the drug industry has stretched the word: companies now say 'therapeutics' as a plural countable noun meaning the treatments themselves ('new therapeutics for asthma'), and hundreds of biotech firms are simply named 'Something Therapeutics'. That business use is now everywhere, but a careful writer keeps the two apart. The related adjective 'therapeutic' is far more common in everyday speech and has drifted well beyond medicine — people call gardening or long walks therapeutic when they simply mean it makes them feel better.