i have big confusion on ppc google campain i saw a website yesterday that site

[satish k]

have a google adwords campain? when see the keyword rank on sponsored links i searched a keyword related to site after that website results in top again i searched same keyword simultaneously result is not as first result and sponsored links result changed.i did like this 4 to 5 times on same keyword.I did not understand we resulting like that i want to know about above problem.and i want to know which is better in google adwords cpm,ppc,ctr,ppa,pps,ctc and explain above and its use and procedure on google