What does a file extension usually mean?

The extension of a file is a string used to identify the file type. It usually consists of one or more letters and follows the file name, separated by a dot in the middle, which can tell the operation How systems and applications process and interpret the file.

The extension of a file is a string used to identify the file type. It usually consists of one or more letters and follows the file name. Behind it, separate it with a dot in the middle. This extension tells the operating system and applications how to handle and interpret the file.

The extension exists to make it easier for the operating system and applications to identify the type of file. In a computer system, each file has a specific format and structure, and different file types need to be processed and interpreted in different ways. By looking at a file's extension, the operating system and applications can determine how to open, edit, save, and process the file based on predefined rules.

In modern computer systems, there are many common file extensions. Here are some common file extensions and their corresponding file types:

.txt: Plain text file. This kind of file only contains text content without any format or structure. It can usually be opened and edited using a text editor.

.doc/.docx: Microsoft Word document. This file format is a document file processed by Microsoft Word and can contain text, pictures, tables and other elements.

.xls/.xlsx: Microsoft Excel spreadsheet. This file format is a spreadsheet file processed by Microsoft Excel and can contain various formulas, data and charts.

.ppt/.pptx: Microsoft PowerPoint presentation. This file format is a presentation file processed by Microsoft PowerPoint and can contain text, pictures, animations and other elements.

.jpg/.jpeg: JPEG image file. This file is a common image file format that can store compressed color images.

.png: PNG image file. This file is a lossless compressed image file format commonly used to store images with transparent backgrounds.

.mp3: MP3 audio file. This file is a common audio file format used to store compressed music or speech.

.mp4: MP4 video file. This file is a common video file format used to store compressed video content.

.html/.htm: HTML web page file. This file is a markup language file used to create web pages and can contain text, images, links, and other elements.

.exe: executable file. This kind of file is a program file that can be run directly and run the application.

In addition, there are many other file extensions, each corresponding to a different file type. Different operating systems and applications may handle extensions differently, and some systems can even determine the safety of a file based on its extension. Therefore, as a programmer, it is very important to understand different file extensions and their corresponding file types so that you can better understand and process different types of files.

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