Nowadays, we can find advertisements almost wherever we go.
We are so used to them that we often do not even realize how many we see and hear in a day.
I did some research on advertisements, and have some very important information to share with you.
An advertisement uses words and pictures to persuade people to buy a product or service,
or to believe in an idea.
Newspapers, magazines, the Internet, radio and television are the most common places to find them.
There are two main types of advertisements--commercial advertisements
and public service advertisements(PSAs).
A commercial advertisement is one which someone has paid for to advertise a product or service.
PSAs are often run for free,
and are meant to educate people about health, safety,
or any other problem that affects public welfare.