compiled/interpreted??

hi while reading use and require modules, i confused with perl is compiled or interpreted.. i read FAQ. but i cudnt understand the following paragraph.. In the following paragraph what is meant by parse tree and What do they mean by front end and backend..Can anyone explain this in detail???

Re: compiled/interpreted??

[is perl compiled or interpreted?] yes. Can anyone explain this in detail??? chapter 18 of 3rd edition of Programming Perl.