Introduction
Reddit is an American social news aggregation, content rating, and discussion website. Registered users (commonly referred to as "Redditors") submit content to the site such as links, text posts, images, and videos, which are then voted up or down by other members. Posts are organized by subject into user-created boards called "communities" or "subreddits". Submissions with more up-votes appear towards the top of their subreddit and, if they receive enough up-votes, ultimately on the site's front page. Reddit administrators moderate the communities. Moderation is also conducted by community-specific moderators, who are not Reddit employees.
Pushshift API
Pushshift is an API for Reddit, not Reddit itself. It's a third-party API that allows you to access Reddit data. Reddit's increasingly hostile attitude towards data access has led to the development of this API. The project started in 2014 and is still maintained by Jason Baumgartner today. For more information read the Pushshift API notes