Which kind of knife is used most often in the kitchen ? why ?

chef's knife

A chef's knife (sometimes called a cook's knife) is the most important knife to have in your kitchen. It has a wide blade between six and ten inches long and is used primarily for chopping, though it can be used for anything you want to do. The blade of a classic, French-style chef's knife curves upward toward the tip.

Explanation:

be confident on yourself. ignore such fools and move on ; )