In China it was known as kê-chiap, in Malaysia as kĕchap, and in England as ketchup; but when the English exported it to the US they decided to call it catsup (goodness knows why).
Ketchup is made from 3 basic ingredients; tomatoes, vinegar, and sugar, with a few spices thrown in for good measure. So, other than the sugar, it's nowt but goodies.
Imagine your fish-finger sandwich without ketchup; no no no! Imagine your local 'greasy spoon' without that ghastly tomato shaped plastic dispenser on the table. Imagine a meal at 'McGrub-u-like' without tear-open sachets of ketchup in-amongst the mayo, salt, and pepper.
I only ever buy one brand (as I'm sure most people do); its container being of such an iconic design, that my version (above) didn't even require the brand name.