Product item: product item means a specific product of the certain specifications and may be distinguish from the other product, or brands. A particular brand of a product is a product item, such as Lux soap, Colgate, Toothpaste, Facit typewriter, H.M.T watch, Rath Vanaspati, television and Bajaj Chetek scooter.

Product line: a product line is a group of different product items, closely related with each other. all the product lines are closely related with each either because they satisfy a class of needs, or used together, or are sold to the same group of the customers, or are sold through the same channel of distribution, or are within the same pricing range. Colgate, Toothpaste, Facit typewriter, H.M.T watch, Rath Vanaspati, television and Bajaj Chetek scooter are the examples of a product line. Here it is appropriate to note that a particular brand of a product is a product item and all the brands of the same product are included in the product line.