Scrum

Scrum is an agile, adaptive methodology. It now applies to general projects as well as software ones Like all agile methodologies scrum uses short iterations and frequent reviews. Additionally the scrum methodology focuses on getting the best possible feature set with the resources available.

As well as the general characteristics of agile development Scrum has two defining features.

Highly formal daily meetings called scrums
A focus on prioritizing features

Many projects fail because key features are late whilst - maybe because - resources are spent on trivial ones. This is not spotted because the focus is on delivering to the plan. Scrum drip feeds features into each iteration 'sprint'.

The Daily Scrum takes the agile ideal of low documentation and constant review to its logical conclusion with daily meetings which follows a very strict format to stop them wasting time. Some of the key features of the meeting are

All are welcome, but only key people can speak - the "pigs" - which are the team, the "scrum master" and the " Product Owner" who represents the stakeholders

The meeting is 15-20 minutes long and happens - on time - at the same time and place each day.
During the meeting, each team member answers three questions:

What have you done since yesterday?
What are you planning to do by today?
Do you have any problems preventing you from accomplishing your goal? (It is the role of the Scrum Master to remember these impediments.)

Other formal meetings occur between "sprints" (Iterations to review the last sprint and plan the next.)

The key scrum features are

Constantly reprioritized features.
Scrums are daily meetings at which the team reviews what is to be done that day.
Short iteration cycles called 'sprints' focussed on implementing a few of the highest priority features from the list.
Group based planning.
a "Scrum Master" who's job is removing all blocks to delivery.
a "Product Owner" who represents the stakeholders in the daily scrums.
the "Product backlog" list of prioritized features giving business value and cost estimates for each feature.
Documentation reduced to a bare minimum by daily meetings.