Cogs allow for each different set of commands to be organized in different files. Cogs also allow the bot to load and unload cogs at will (meaning you can make changes on GitHub, pull those changes into the bot, then reload the cog that was affected by the changes without having the bot go offline).
https://discordpy.readthedocs.io/en/stable/ext/commands/api.html?highlight=cogs#discord.ext.commands.Cog