Facebook is one of the leading social media platforms out right now. They have been out for some time now and have been dominating their sector. As they continue to grow in users, their features and capabilities continue to expand as well. It has multi-use purposes from seeing what your friends are doing or thinking about to marketing your business. The possibilities are endless.
Nextdoor is aiming to become as large and widespread as Facebook. Facebook and Nextdoor both are shooting for the same goal, which is to help their users. Facebook has features to which you can have make groups with different types of people, whereas Nextdoor is solely based off the grouping factor. With Nextdoor, members are grouped with their neighbors based off their geographical location for their social feed. Facebook groups are usually made to just sell items, announce events, and things of that nature which is pretty much the base of what makes up Nextdoor.
I suggest that you check out Facebook for yourself here: http://www.facebook.com