In one sentence, describe what the following article is about:

Hamsters are very active and need lots of things to exercise in their cages, getting a wheel is a good place to start. Dwarf hamsters need a 6.5 - 8 inch wheel and Chinese hamsters need an 8 inch wheel. Larger hamsters, including Syrian hamsters need a 12 inch wheel. It's very important to get a wheel that is big enough for your hamster. Flying saucers cannot replace a normal upright wheel, as it encourages an unnatural way of running. NEVER use barred or mesh wheels, as your hamster can trap a limb or get bumblefoot (painful sores on the feet). One way to tell if it is too small is to look to see if your hamster is running with an arched back, like a smiley face. If they are, then the wheel is likely too small. If you buy a bottle, buy a good one that doesn't leak too much. If you get a bowl, buy something like a small bendy log bridge to put over it so that your hamster doesn't bury it or get wood shavings in it, or you can place the bowl on a small shelf. Using a bowl enables you to keep a good track on how much they are eating, and can be cleaner and easier. However, using scatter feeding brings out the hamster's natural foraging skills. You can also do a mix of both. If you have a pair of dwarves, then scatter feeding is advisable as it can prevent fighting. If you have a Chinese hamster (note! Not dwarf hamsters. Despite what a pet shop may have told you, they're solitary like Syrians, even the males) or a Syrian hamster then it is advisable to get a food bowl so that you can check their eating habits. If you get a bowl, buy a small one so it doesn't take up too much cage space. Most houses are suitable for dwarf hamsters and Chinese hamsters, but many are much too small for a Syrian hamster. Bendy bridges can be turned into lovely cave-style houses if you bury them under the substrate! Some hamsters make nests, but they need somewhere to hide and store food anyway. Hamsters are very energetic and need lots of toys. Make sure to get chews as their teeth never stop growing! Hamsters love toys that they can climb and hide-and-seek style toys. Get some tubes, too - they're no replacement for digging but hamsters love running through them! Make sure that they're big enough, though - many tubes aren't big enough for Syrian hamsters. Also check that they have ventilation, as if they are long tubes your hamster may have trouble breathing in them.

Summary:
Buy a wheel. Buy a water bowl or a bottle. Decide whether to get a food bowl or scatter-feed. Choose a house for your hamster. Buy some toys.