How does comcast host internet? Like what does someone need to do to host internet?

I have always wondered this I mean they sell internet for so much but how do they get it? How would someone be able to get a direct connection to the internet without having to go through say comcast? I mean comcast has a direct link to the internet some how right?

Internet Service Providers use the telephone and cable lines on the poles to give people internet. You are paying them a fee for them allowing you to use their lines.