Scrum is a framework or rules that allows you to tailor your own lightweight process to develop new products. Scrum is simple, it can be understood and implemented in a few days, but it takes a lifetime to master.
“Scrum is not a methodology – its a pathway” Ken Schwaber
Scrum will also help you fail in less than 30 days. Unlike the waterfall method where the product is fully developed and then sent for testing. Scrum works in iterations of 30 days (or less if you have chosen short sprints). Each Scrum Iteration will aim to have potentially shippable code at the end of the iteration. This can then be tested and demonstrated to the customer. If the product developed does not work due to technical problems or it is not what the customer wants, then this will be found out within the 30 day iteration and can be subsequently dealt with. This is the opposite of the waterfall method, where it could be potentially a year down the line until you find out that your product does not work as expected or it is not to the customers needs.
Also, Scrum can also cater for the ever evolving needs of the customer. Code built using the waterfall method are often planned over a large timescale depending on the size of the product. It may be, that by the end of development the customers needs have changed and therefore the product being developed may be obsolete and may need further development to get re-tailor it to the customers needs. With Scrum, we can track changes and enter these into the backlog. By evaluating and adapting, we can better tailor the product to the customers needs sooner rather than later.