How can I decide what bike I should get?

When it comes to bicycles for adults, there are different kinds available in the market. Select a bike based on how you'd like to use it. Bikes can be categorized as follows:
1. Road bikes - These bikes have super thin tires and are often used for biking on roads. These help you attain high speeds relatively quickly.
2. Mountain bikes - These bikes are made to sustain the rough terrain that you could come across while biking. The tires are much thicker and made to protect you and give you the support you need.
3. Hybrid/Commuter bikes - These bikes fall into the middle of the above 2 categories. If you think you might do a bit of road biking and mountain biking, then this might be your best option.
You can also go to a store that specializes in selling and repairing bikes to get more information.