Coalition, Common, and Universal College Applications?

What are the differences between the three applications systems?

These are examples of college application services that provide standardized
Applications, which allow you to apply to multiple schools with a single
Application. Instead of filling out ten different applications, you can simply fill out one and submit it to each college.

The Common Application is a standardized application used by nearly 700 colleges. Nearly a million students use the Common Application to submit over 4 million application.

The Coalition Application is accepted by more than 90 institutions and the Universal College Application is accepted by more than 30 colleges.