After the tooth is reduced, a crown is placed over the top. The color and type of crown is done to fit and blend perfectly with the neighboring teeth.
Having a crown does not mean you now have a fake tooth. It is your natural tooth underneath. You will still feel hot and cold. You can chew normally; you will be able to floss normally. It is still your tooth.
A crown does not mean you have to have a root canal. However, the reverse is true: if a tooth has a root canal, a crown is now recommended. A root canalled tooth is hallow and thus fragile to breaking. A crown strengthens a fragile tooth. But just because a tooth has a crown does not mean it will need a root canal.