kiswah03 0 Newbie Poster

hi, I want to create an application in netbeans which send input and retrieve result from a website. I googled this... Some say we have to use jsoup, some says we have to use selenium , some says ajax and some says jquery. I am totally confused. i read so many turitorials on all these, but could'nt find a solution which explains it in a easy to undertsand way.
As i am new to creating web based application, some one please do guide me to the right solution. Can anyone please explain by using simple example . please..................
for example, in this following website http://www.math.com/students/calculators/source/square-root.htm to calculate square root, i need a software which will give value to the number text field and retrieve result from square root text field. Please help me...please...