It is difficult to type long command frequently in Linux/Unix and then we need to make it short for our convenient. You can make the commands short in Linux/Unix by creating aliases for it. Below is the example given to create alias for a command in Linux and Unix.
Suppose you need to type the following command to navigate to the particular directory again and again:
$ cd /oracleapp/myprojects/20121010/file1/forms
You can create the alias for the above command to create a shortcut to accomplish the same task. In the below example we will use the alias myd for the command and make sure the alias must not the reserve word of Linux or Unix.
$ alias myd='cd /oracleapp/myprojects/20121010/file1/forms'
Now you can enter just myd to navigate to the target directory.