-MS-DOS is a popular operating system.
-It is a single user operating system.
-All letters must be capital.
-IO.SYS are hidden files and they don't display in the directory.
-COMMAND.COM provides the explanation for all the comments in dos.
-The DOS has 2 types of comments(Internal Comments, External Comments)
Difference Between Internal Comments and External Comments :
-Internal Comments are loaded during the booting process and are always avaliable in the memory.
-External Comments reside on the hard disk and they must be loaded in the memory before the execute.
