Let’s get this out of the way before we go any further. Bike fenders / mudguards are not cool.
But boy are they useful if you cycle in a climate like ours.
There are, broadly speaking, two types of fender / mudguard: those for frames with mudguard eyes – ‘fixed mudguards’ – and those for frames without, known as clip-on mudguards. Of course even if your bike has mudguard eyes there’s no reason why you can’t use clip-ons if you’re looking for a lightweight, easily removable solution.