Panniers, hanging from a rack at the back of the bike, are the classic cycling luggage, but many people like a rucksack for the office run and there's a whole new genre of frame-mounted bags for fast, light 'bikepacking' rides.
Road.cc articles on bags and panniers
Beginner's guide to cycling luggage — how to carry stuff on your bike
Your guide to racks and panniers — all your bike luggage possibilities from low riders to convertible backpacks
10 of the best cycling rucksacks