Leechers consist of those still in the process of downloading a file. A leecher can also be someone who stops sharing a particular file they have downloaded through a torrent client. This happens when a downloader closes the torrent program upon receiving the finished download.
While it is required that a downloader be a leecher when a download begins, a leecher may become a seeder when the complete file is downloaded to their machine. A seeder is simply a computer that has the completed file and is actively allowing it to be shared with other downloaders.
After a torrent file has finished downloading, it is polite to continue seeding it to others until the ratio of uploaders to downloaders is at least 1.00. All that's required to do this is leave the torrent program running. If for some reason you don't want to continue seeding a file (thus becoming a leech), you can remove the file from your torrent client or close the client to stop seeding.
Seeders are the people that have the files and share with others
Leechers are the people that don't have the files and download them from seeders
It's don't matter which one is higher. When seeders are more than leechers then the download speed is higher but when leechers are more than seeders it not always mean that download speed will decrease.