Patents and copyrights encourage innovation because they allow people to be rewarded for their creations. For example, if an individual creates a new type of cell phone they can receive a patent or copyright on that phone. This means the ability to make and sell this phone belongs solely to the individual or the company they represent.
Now if this cell phone becomes wildly popular and people start to buy it, it allows the creator to make a significant amount of money of their creation. Along with this, the person can sue any person who tries to take their design and sell the phone themselves.
Ultimately, patents and copyrights protect people who come up with amazing innovations and allows them to accumulate massive amounts of wealth.