Prepend

A shell lets you define variables (like most programming languages). A variable is a piece of data that is given a name. Once you have assigned a value to a variable, you access its value by prepending a $ to the name:
$ bob='hello world'
$ echo $bob
hello world
$

Variables created within a shell are local to that shell, so only that shell can access them. The set command will show you a list of all variables currently defined in a shell. If you wish a variable to be accessible to commands outside the shell, you can export it into the environment:

$ export bob

(under csh you used setenv). The environment is the set of variables that are made available to commands (including shells) when they are executed. UNIX commands and programs can read the values of environment variables, and adjust their behaviour accordingly. For example, the environment variable PAGER is used by the man command (and others) to see what command should be used to display multiple pages. If you say:

$ export PAGER=cat
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I am working with the scripting language. My question is on the word 'prepend'. Do you find it in English?

I know the word 'append' exists in English.