Flash is a very capable platform for one simple reason. It combines animation, wide compatibility and business logic in a single package. It also has a tremendous high-quality integrated development environment which makes it a big hit with developers. Because of its wide-ranging success, Flash has been used for every kind of application from video players to games to accounting packages.
The Flash game industry reached its peak around 2010 and helped build companies like Armor Games and Miniclip into industry leading publishers. Using in-game or "pre-roll" advertising as their main revenue source, Flash developers relied on simple, casual-style games to appeal to the widest possible audience. The results were impressive, and demonstrated once and for all video games were in demand from nearly every demographic group.
The most popular types of Flash games were puzzles, dress-up games, 2D driving and action games and the occasional educational title.
Simply put, YouTube wouldn't exist without Flash. The ability to present high quality streaming video in a web plugin is one of the technologies that made sites like Amazon Prime, Netflix and YouTube possible. Flash was the vehicle that not only allowed audiences to watch videos, but to control them and play them back at full screen resolutions as well. Many sites still rely on Flash to provide a consistent player interface for their videos, mainly because Flash still offers the best combination of reliability and functionality.
Enterprise-class business applications often rely on a multi-tier (or "n-tier") architecture in order to separate data from business logic and business logic from the user interface. Because of its high quality programming language and access to a wide variety of standard APIs, Flash is often used as the user interface layer and presented in a web browser. This helps developers avoid incompatibilities in browsers and instability in the event of a major software update at the client level.
Storyboarding and Animation
At its core, Flash is an animation platform, so it stands to reason it would be popular as a storyboarding and presentation tool for animators. Its easy integration with the rest of the Adobe Creative Suite makes it popular with designers as well, who can use the same technology to present their concepts in a working form even without doing heavy programming work.
Flash remains one of the great accomplishments of web technology and is still heavily utilized in many industries because of its quality professional support for web standards and Internet protocols.