A ".txt" file is a simple text document that contains plain text without any special formatting. It is commonly used for storing notes, lists, or any other type of written information. Because it only includes text, it can be opened and edited by many different programs, such as Notepad on Windows or TextEdit on Mac. One of the main advantages of ".txt" files is their compatibility across various devices and operating systems. This means you can easily share a ".txt" file with others, and they will be able to read it without needing specific software. This makes ".txt" files a popular choice for sharing information quickly and easily.