Definition of Agile
Time-boxed – Time-boxed means all the activities/iterations/ceremonies are time constraints. There is no endless, limitless time approach. At the end of that defined time limit, output should come.
Iterative – Iterative model is successive upgrade of a project. For example if we have to make a greeting card, we shall first create frame, draw the figures, then colour it and then decorate and complete it
Incremental – Incremental is piecewise delivery. With the same example, it we are making card incrementally. We shall create one part of card completely and then increment it with next small part and it will go on till completion
Business Value – How important is this feature to Customer? Or How badly this feature is needed/not needed by customer defines the Business Value of the features
Agile is combination of all these. Where by following time-boxing, we incrementally iterate and release potentially shippable product after every iteration. This potentially shippable product is the one driven by business value as the features in it are prioritized by Customer as per their requirement.
Focus on Business Value is a core aspect. At the end of iteration, the success of work is achieved with a quantum of value delivered. Potentially Shippable Product with a business value delivered with it in each increment is foremost important in Agile environment.