In the early days of the online casino industry, you would need to download and install a program to your computer before you'd be able to play. This was a problematic restriction because it put players in a position of typically needing a Windows-based PC, and it made it difficult to play from shared computers. Thankfully, instant play options are available now that eliminate a lot of the disadvantages of downloaded platforms, but they have some of their own disadvantages that will affect some players.
The basic way that an instant play platform works is that it will use Adobe Flash and/or HTML5 to give players a complete casino that runs inside of their Internet browser. You'll navigate to the site, log in and start playing right away. This makes it easy to get started quickly, but it also makes it easy to get started playing from any computer. That makes it perfect for players who have to switch computers frequently or who play from computers that other people access on a regular basis. You don't necessarily want people all in your business knowing which online casinos you play with, and this can be a simple way to avoid having that conversation in the first place.
In the past, especially when instant play options were first starting out, there were some major game selection issues. Many games would be released to the downloadable platform only, and this meant that playing on an instant play option would give you fewer game options. This isn't really an issue now since instant play platforms are the most popular way to play, and virtually every major online casino software developer releases their games on all platforms at the same time. This means there are no longer gaps between the release dates for downloadable and instant play versions of the same title.
One aspect of instant play games that can become a disadvantage is that there are loading times for the games to come up on your computer when you play through an Internet browser. Because they aren't stored on your computer like they would be with a downloadable platform, you have to account for the time it takes for the game to load. Along these lines, people with slower connections can end up waiting longer than others, and that can be one disadvantage to using an instant play platform.
In an effort to help out players who might have slower connections, it's the case that most instant play games will have slightly altered graphics compared to their downloadable versions. The reason for this is simple: Some small changes to graphics can lead to sizable improvements when it comes to loading times.
Something that's really cool about instant play platforms is that they can be accessed on mobile devices as well. This helps out players by giving them a one-stop-shop type of solution where they can access the same games with their computers, smartphones, tablets and other mobile devices. All you really have to watch out for with this is that you're set up with a WiFi connection because playing over 3G or 4G can really run your data usage up quickly, and that's something many players want to avoid.
Overall, instant play platforms are the platform of the present, and they're likely to also be the platform of the future. They have a number of advantages, but there can be some small disadvantages depending on your particular circumstances. Thankfully with advances in technology, loading times aren't really an issue anymore for most players, but it's still something that's worth keeping in mind before you get started playing.