Can anyone suggest me a source from where i can understand the meaning of terms like "sourcing the environment", "repository", "chef", "clone", "environment variables", "git" etc.. I need a source that explains all these and related terms in very basic language, coz i am totally ignorant in these (i dont even know where to look for these, i guess its UNIX related) and its kind of very very urgent.. I want a thorough understanding as to what these are and what they do, not just the above mentioned terms, but everything related.. I do not want any source on UNIX commands, but an understanding of what the above mentioned terms.. Plzzz help..