want to know Online trading process

#1
Hello, everybody.
your posts are very useful as I am a beginner in this market.
I have a small confusion:
At the time of intra day buying of selling shares through online,we have to input the share qty. and the price value.Suppose I want to buy some ABC company share ,whose value is right now 25.25, Now I want to buy 10 shares of it,so I should input 10 in Qty tab of the online trading interface,but what should I input at the price value tab?
If I input 26.00,and place the order,what does it mean,when the price of the share will 26.00, 10 nos share will be allotted to me.
If I input 25.25 at the price tab what will happen?
If suppose at the end of the day the price of the share falls from 25.25 to 23.65 and it would fail to reach 26.00 value, do my order will cancel or what will happen?

Please someone help me on this topic....