what is difference between concentrated and diluted???

Well diluted means making a solution thinner by adding something else like water. It also can have mean lessening or decreasing. Concentrated is the opposite - to increase. An good example is liquid laundry detergent...now they come in smaller bottles that are more highly concentrated...the solution is now more powerful so you need less. Before in the big bottles they had more water to dilute it so you had to use more.