Hi, it would depend where you are looking in the tool, average response time could be for the entire page or transaction. Request response time are the individual requests themselves. Take the page you are looking at now, there is the text, several images, a style sheet, maybe some java script. It's just the level of granularity the average is taken on. In terms of percentiles, that's the average of 90% of the responses. Imagine values 1,1,1,1,1,1,1,1,1,10, one bad penny is spoiling out average (=1.9), if we only average 90% of them (low to high), we get an average of 1. Basically what is the level of performance the majority of our users see.