Online casinos are typically defined by the technology they use or by the kind of games they offer.
Download casinos are those that run locally on your computer or through an app on your mobile device. You have to download a piece of software to to play them.
Read more on Download casinos
Browser based casinos
Becoming the new standard for online casinos, those that play in the browser can run on a variety of technologies such as Flash, Java or HTML5. The best of these casinos will run fast and smooth even on tablets and mobile phones.