But what are the key words? I'd also appreciate the help. Thanks in advance~
In this case, "key words" would be words or phrases that are mentioned in the job ad. For instance, if you're applying to a Web development job, they may ask for .NET, Java, PHP, MSSQL or MySQL, or any number of programming languages or platforms. Those would be the key words.
Those automated systems drive me crazy. If I've got 20 years of experience as a programmer, and I know eight of the ten things listed in the ad, my resume might not even make it past the automated filter because I'm missing two of those things - even if they're fairly minor elements which I could learn in a couple of days with a manual. (Admittedly, the same issue exists when a company has its HR department vetting the resumes manually - your average HR person will look at a resume and say, "This guy has MSSQL, not MySQL, so he's obviously not a match." Which is ludicrous.)