An FLA file is an animation project created by Adobe Animate, a program used to draw and publish interactive animations. It contains graphics, video, text elements, audio, and other assets. FLA files are often saved as .SWF files for use on the web as they are viewable in most web browsers with the Flash plugin.
When you open an FLA file in the Animate environment you will see five main parts. The environment includes a stage that shows the visible area, a timeline that controls the timing of the elements, a tools panel that contains tools for working with elements in the project, a property inspector that displays information about elements, and a library panel that stores media elements.
NOTE: Animate was formerly known as Flash, which was originally developed by Macromedia but then merged with Adobe in 2005. Flash became Animate in 2016.