The Kids Of Degrassi Street
This logo was used for the original show which was only 26 episodes long, which ended in 1986.
Degrassi Junior High
This logo was used for the 3 seasons of Degrassi Junior High, followed by Degrassi High.
They used this logo for 2 seasons of Degrassi High, which ended in 1991. After Degrassi High there wasn't any Degrassi until 10 years later when Degrassi: The Next Generation came to TV. Despite the TV movie "School's Out" that was released in 1992.
This was the movie that was released a little after the finale of Degrassi High...next was the premier of Degrassi: The Next Generation that premiered in 2001.
Degrassi: The Next Generation
This was the logo for the first 9 seasons of the show.
Degrassi: Next Class