ANOVA T TEST

I am doing processes in Rapidminer for some times, but because I have not very deep understanding of statistics I am sometimes wondering on one thing - what are the ANOVA and T TEST for? Cannot somebody give me very simple idea? Has it some place in selection of the data or features of the data or is it suitable for evaluating or comparing results? Is there somewhere some proces on MyExperiment or anywhere which is using it? What task it have for instance when I am doing regression task?
Thank you,
Milan