Affiliate Marketing involves you selling someone elses product and recieving a split of the profits for your work! Items range from Ebooks, software, games, website scripts, etc. even physical products, But mostly affiliates tend to go for digital products as they tend to pay higher and instantly as customers only need recieve an email or be redirected to a thank you page with a link to download their product.
Affiliate Marketing at its very basic level just involves you aquiring your affiliate link that will send visitors or those interested to the salespage containing the product you wish to promote, then finding where those interested in the product might hang out and getting involved in discussions and conversations on the topic of the product before offering to help out by sending them to your affiliate link and the product that can solve their problem.
At which point if they buy something you get paid a cut of the sale!
But some more advanced affiliates like to direct there traffic/visitors to what they call a “capture page” and the purpose of this page is simply to offer them a free gift such as a ebook or informative bit of information such as a video, etc. in return for them giving you their email and signing up to your list, after which they are redirected to the salespage to whatever product they’re promoting.
And even if they dont get a sale they can then market other products to the subscribers at a later date and make money several times over rather than if they sent the traffic/visitors directly to the products salespage!