Waterfall is the traditional way that businesses accomplish things. It's main characteristic is it's linearity. It like one of those Discovery channel car shows. Someone brings them an old car, the customer (usually pretty vaguely) tells the boss what he wants to be done. Then a routine build is dramatized for TV (not enough time, ordered the wrong part, scratched the paint, etc.). At the end, the customer comes back swearing that the car is exactly what he had blurredly envisioned from the beginning.
At the beginning of traditional work flow the requirements for the product are all established, and in the middle the creation process, usually monitored, is carried out until the product is complete. The problem with this is that customers usually can't tell you what they really want, they don't generally have enough knowledge of the complexities of the software to accurately describe what they want in the beginning.
Agile development exists to solve this problem. It consists of fixed time sprints, where a specific part or iteration of the project is completed. It's more user focused and can more easily be used to produce a usable prototype more quickly. It requires customer involvement and decisions which might not be good for those with scarce time or interest in the process.
The best of those car shows are the ones that cut down on useless drama to actually educate you. They dramatize the actual difficulty of satisfying the customer. They might show the customer being shown renderings of possible looks for the car, or coming to look at the project and being dissatisfied. Sometimes the boss has to work around the customers restraining budget, being as flexible as possible for the sake of the customer. Find out how Contensive will adapt for your needs, please contact us.