What is Affiliate in computer parlance? It is nothing, but, an agent or representative of other website. For e.g. Website "A" is a shopping website. Website "B" is your website containing useful information for visitors. You can include code of Website "A" to your website "B". Then, Ad of Website "A" will get displayed in your website. When visitors of your website clicks on the ad of Website "A" and purchases products from Website "A", you will be paid commission by Website "A". That means, you earn some money. If your website has many visitors and if some visitors go to website "A" from your website, this is an added revenue.