The former is hypertext tag hypertext Markup
The latter is the Hypertext Markup Language hypertext Markup Language
Can say HTM = html
At the same time, both of these are static Web file extensions, extensions can be exchanged without causing errors (this means open, but for a link, if it points to an HTM file, and the HTM file is changed to an HTML file, then the connection is not found)
So why are there two file formats?
HTM is derived from the old 8.3 file format, the DOS operating system can only support the length of the three-bit suffix name, so is the HTM, but in Windows does not matter the HTM and html,html is a long file name format named. Therefore, the HTM is to be compatible with the previous DOS naming format exists, there is no difference in effect. Previous HTM and HTML as hypertext files on different servers, but now generic.
What is a 8.3 file format? This is a short file format in the old 16-bit WIN95 or Win98 file system, the extension is limited to 3 bits, and the file name is limited to 8 bits. If you want to interact with a 16-bit system, for example, to pass a path to a 16-bit program, you cannot use a long file name, and you must convert it. For example, convert "C: /mylongestpath/mylongerpath/myfilename.txt" to "C:/mylong~1/mylong~2/myfile~1.txt"
What's the use of knowing this? In the FAT disk format of the DOS only support 8.3 file format, if you want to do the application in this environment, you should pay attention to this file format problem. Under NTFS, this format is compatible by default, and long filenames are supported, and you can also cancel the 8.3 file format by adjusting the registry.
Thanks http://wenku.baidu.com/link?url= 2kj2bglfi3fhknk0pr3falmdmlr-jqg6fd9fabdlqtfbnnhyvly-nijpgm5rsbdv8oq72xtfla5i23uolnc3s1_ Qe8mrdhy-0akf56jna3o Author's share
The difference between HTML and HTM