A few manufacturers offer a replacement lamp and a lamp module for their projectors. A lamp module means you are buying a complete unit - this means the lamp and the housing around it. They are intended to be user-replaceable and no advanced technical knowledge is needed to replace them. If you have the option to buy a lamp only for your projector, you will need a degree of technical expertise to replace it. By buying just the lamp you do not get the 'housing' around the lamp and changing it can be a difficult job, often resulting in damage. Whilst a lamp only might be slightly less expensive, we highly recommend you purchase a lamp module if you do not already have extensive technical knowledge of projectors and/or electrical hardware.