OpenTopography data can be downloaded in LAS, LAZ or ASCII file formats. The following list describes each dataset type.
LAS: (from ASPRS): "The LAS file format is a public file format for the interchange of 3-dimensional point cloud data between data users. Although developed primarily for exchange of lidar point cloud data, this format supports the exchange of any 3-dimensional x,y,z tuplet. This binary file format is an alternative to proprietary systems or a generic ASCII file interchange system used by many companies. The problem with proprietary systems is obvious in that data cannot be easily taken from one system to another. There are two major problems with the ASCII file interchange. The first problem is performance because the reading and interpretation of ASCII elevation data can be very slow and the file size can be extremely large, even for small amounts of data. The second problem is that all information specific to the lidar data is lost. The LAS file format is a binary file format that maintains information specific to the lidar nature of the data while not being overly complex."
LAZ: The compressed form of a LAS file.
ASCII: Stands for American Standard Code for Information Interchange. ASCII files are text files containing information about the points in a dataset organized into columns. To define a point cloud, ASCII files must have x,y, and z point columns. The ASCII format is not unique to 3-dimensional point cloud data.