TXT is one of the simplest and longest existing text file formats. The full name of the format is Plain Text File, and the developer is unknown. Text files of this format are very small, and therefore have become very widespread. A TXT file contains text data organized as strings. As a rule, this is a standard text document without formatting. This format is universal, it is available to work in almost any text editor. But one of the simplest and most common is Windows Notepad. Files with the extension .txt are associated with this program by default.
ODP is the native text file format from the OpenOffice office suite (or Apache OpenOffice). The format was developed by Sun Microsystems. Its name is an abbreviation for OpenDocument Presentation. The ODP extension is commonly used to create presentations. To create ODP files, the open XML standard OASIS OpenDocument is used. Since 2010, the popular Microsoft PowerPoint program can also work with ODP files. A presentation in ODP format can exist in the form of a set of slides, which include text (including formatted), graphics, various effects.