Alright, guys.
LAG refers to "latency" Latency is the rate it takes your computer to communicate to the server that you're connected to. This is measured most often in milliseconds. Having a lot of lag is almost exclusively because of a bad internet connection, server problems, or a geographically significant distance between your location and the server's location.
FRAMERATE refers to how many frames per second of any media that your computer is capable of processing. In this case, the media format is a flash game; the framerate, or FPS, is how many still images (frames) per second you see. The higher your FPS, the more it looks like fluid movement on-screen rather than a series of still images. Having low FPS is usually an issue with your computer's specs, your settings, your drivers not being updated, outdated programs, etc.
If you want any amount of help, PLEASE don't use the word "lag" without explaining to which you're referring.