HMO OR PPO?

Jessica
Hello ladies!!
I have a question I just got Blue Shield Insurance through my job - currently I have PPO because I assumed its the best. I plan on having natural birth because I have acute scoliosis. I do not really know the difference - does anyone have some pros and cons for both HMO and PPO for me please. I have not even picked a doctor for my insurance and ive had it for almost 3 months now 😑
- Jess