Q. What do you mean by Keyboard Touch?
When employing a keyboard the most important factor is the feel of keyboard it implies that how typing feels on that specific keyboard. Keyboard should respond appropriately to your key press. This not just means that keys should go down when pressed and then come up but also that there should be a certain feedback to your fingers whenever a key gets activated. This is essential for you to develop faith in keyboard and enable fast as well as reliable typing.
Linear travel or linear touch keyboards raise resistance linearly with travel of key. Thus you have to press harder as key goes lower. There can be audible feedback as a click and visual feedback as appearance of a character on screen allowing you know when a key gets activated. Better keyboards offer tactile feedback (to your fingers) but abruptly decreasing resistance when key gets actuated. This is known as an over-center feel. These keyboards are best for quick touch typing. These were implemented by employing springs earlier however now they are generally elastic rubber domes. Keyboards also are different in whether they 'click' or not (soundless) on the force needed and key travel distance to actuate a key. The choice is generally an issue of personal liking. Laptops typically have short travel keys to save space that is at a premium in laptops.