What is a PSA or Public Service Announcement:

A PSA or Public Service Announcement is a small segment of safety or information that can be useful in life. An example would be if a local doctor were giving free classes to help the elderly fight lung cancer. This doctor could take out a PSA on any media outlet to promote this service without being charged. Anyone who is trying to inform the public of a service or a safety hint can call any media outlet and obtain the privilege of a Public Service Announcement.