There is only one file type that uses the .LAS extension:
LIDAR Data Exchange File
File created in the standard LAS format, which was developed by the American Society for Photogrammetry and Remote Sensing (ASPRS); stores Light Detection and Ranging (LIDAR) data that is collected by optical remote sensors; used to exchange LIDAR data between data providers and data consumers.
The LAS file format was developed in response to the growing number of proprietary LIDAR file formats. It also was designed to overcome some of the complexities in existing LIDAR data. LAS files are stored in a binary format.
Updated: September 30, 2014