TXT is a file format that contains the text, organized in rows. Text files opposed binaries that contain data that is not intended for interpretation as a text (encoded sound or image). The text file can contain both formatted and unformatted text. Since the very simple text files, they are frequently used for storing data.
This is a graphic file format that supports HDR. It is used for exchanging graphics data between applications. It is also used for development in the Netpbm suite of graphics editors. A PBM image has either a per-pixel RGB structure or instructions for representing grayscale tones.