apocalypse_gold has already answered your question. a "Buffer" solution is a solution that is buffered to maintain a certain Ph. At work we have fisher brand buffered solutions for our Ph probes. Ph 4, 7, and 10. they also sell packets that are mixed with DI
water to form the solution.
If the solution wasn't buffered you would not know the exact Ph of it. ie carbonic acid will decrease the Ph of the solution and therefore the calibration curve for that instrument would be in question.
Normally you have to have 2 solutions inorder to calibrate a Ph probe. The two should be bought that closest match what you will be measuring.
Oh, and one other thing. the solutions should be at a set temperature when calibrating the probe. the ideal temp is 25 +/- 5 degrees C.
In order for me to say which solution you need i have to know what probe and what instrument it is connected to.
but from the sounds of it all you need is the ph
10.01 and 7.01 buffer solutions. It would be a good idea to get the storage solution also. If not, the potentials of the Ph probe will get clogged up and render the probe useless. you can make your own storage solution if you have access to KCl. just add some KCl to the Ph 7 buffer and you will be all set.