Affiliate marketing allows you to recommend products and services from other companies and be paid a commission if someone buys the product as the result of your recommendation. To track which purchases happens as a result of your recommendation(s), the merchant will provide you with a special link to use when linking to their website that contains a unique referral code assigned to you. If people click that unique link, and buy the product or service within a specified timeframe (the timeframe varies depending on the merchant), you get a commission on the sale.
Teaching and tutoring English as a second language is a great way to make money online, not to mention open some doors for you to travel the world if you'd like. While full ESL (English as a Second Language) accreditation is recommended, as long as you’re a native speaker and have the ability to teach, there are people in countries such as Hong Kong or the UAE who are willing to pay upwards of $25/hr for you to tutor them English via Skype. Check out Indeed, Learn4Good and Remote.co for remote english tutoring jobs or sign up on a specialized site like VerbalPlanet or Chegg Tutors.