It is an alternative form of Testing, where some colleagues were invited to examine your work products for defects and improvement opportunities.
Some Peer review approaches are,
Inspection
It is a more systematic and rigorous type of peer review. Inspections are more effective at finding defects than are informal reviews.
Ex: In Motorola's Iridium project nearly 80% of the defects were detected through inspections where only 60% of the defects were detected through formal reviews.
Team Reviews: It is a planned and structured approach but less formal and less rigorous comparing to Inspections.
Walkthrough: It is an informal review because the work product's author describes it to some colleagues and asks for suggestions. Walkthroughs are informal because they typically do not follow a defined procedure, do not specify exit criteria, require no management reporting, and generate no metrics.
Or
A 'walkthrough' is an informal meeting for evaluation or informational purposes. Little or no preparation is usually required.
Pair Programming: In Pair Programming, two developers work together on the same program at a single workstation and continuously reviewing their work.
Peer Desk check
In Peer Desk check only one person besides the author examines the work product. It is an informal review, where the reviewer can use defect checklists and some analysis methods to increase the effectiveness.
Passaround: It is a multiple, concurrent peer desk check where several people are invited to provide comments on the product.
