Jojo's Bizarre Adventure seasons?

I'm watching the anime right now.

Most say the show has 5 seasons or so; I only watch 2 on Netflix.

Once ' Season 1 '' and ' Stardust Crusaders ''

I'm through with season 1 with the first 15 episodes.

First it was about Dio and Jonathan Joestar. Since they are both dead, now it's about Joseph Joestar (Jonathan's grandson?), Right?

This whole Dio and Jonathan thing was back-story, right? I feel like I got it right, but I'm unsure.

Besides, where are the other seasons?

There are 5 parts

Part 1 Phantom Blood and Part 2 Battle Tendency are both on Netflix as one season. Part 3 Stardust Crusaders is actually seasons 2 and 3 but combined as one season on Netflix. Part 4 Diamond is unbreakable is not available on Netflix but you can see it on Crunchyroll (or other sites. Part 5 Golden Wind is also not available on Netflix. Part 6-8 is only available as a manga and you are still waiting for the anime other question no that's all story only Araki (the mangaka) decided to do something different and that's why it went this way. I think every part has its own charm and that's why it's my favorite anime because it is different the other very different.

You took it right. Everything then builds on Part 1 and is always adequately explained / illuminated in the course of the story.

All episodes and the 3 compilation films are available on Crunchyroll.

Part 1 would be Phantomblood (episode 1-9)

Part 2 Battle Tendency (episode 10-26)

Part 3 Star Dust Crusader (was split but is a part with 48 episodes)

Part 4 Diamond is Unbreakable (39 episodes)

Part 5 Golden Wind / Vento Aureo (39 episodes)

Part 5 was the last part to be animated. If you want to read on, the following parts are called:

Part 6 Stone Ocean (158 chapters / 17 volumes)

Part 7 Steel Ball Run (95 chapters / 24 volumes)

Part 8 Jojolion (currently still running 100 chapters / 23 volumes)

Have fun.