How Beatport work?

I have been hearing a lot about Beatport recently, from DJs to the producers, but i am not 100% sure how it actually works. I only know that it is a platform it is buying and selling platform foe electronic music, but does only DJs use it or general public can also use it? And also how do the top 100 chart works, because i have seen people talking about comming the song in the top 100 chart. Does coming in top 100 chart on the beatport depands upon the number of sales or other things also matters?

If anyone can help it will be great!!!!