I know that nowadays, DOS & UNIX aren’t that popular as anyone barely uses Character User Interface rather prefer Graphical User Interface but if you are a PC user, the transition to Unix will be easier for you because of the similarities between DOS and Unix.
One similarity is the hierarchical file system. As in DOS, Unix provides you with the ability to create directories so that you can organize your file system as you prefer. However, since Unix is a multi-user system, you will only have permission to create, modify, and delete files in the part of the file “tree” allocated to you. You can move around in the entire file system, for the most part, looking at and even copying files that are accessible, but you can only write files in your own area.
File names on the HP-Unix system can typically be much longer than under DOS. The maximum length for file names is 255 characters. File extensions can be longer than three characters; in fact, you can include more than one period (.) in a filename (for example, car.engine.block). Path names (complete file name and all directories associated with it) can not be longer than 1,023 characters.
Another similarity is in the command names; many basic Unix commands will be familiar to the DOS user. You will notice that a number of Unix commands are only two letters, contributing to the reputation that Unix is too cryptic. Once you’ve become accustomed to these terse commands, however, you will probably appreciate the few keystrokes required. Also, if you prefer names for commands other than what is provided by default, Unix systems provide the capability to ‘‘alias’’ a command (including your favorite options) to any name you prefer. The information on how to create command aliases is found online by typing man ksh (for the Korn shell) or man csh (for the C shell).