Poker Cards is a tool used by an Agile team in planning and estimating tasks. Usually, the product owner or customer reads an agile user story or describes a feature to the estimators.
Each estimator is holding a deck of Poker cards with values like 0, 1, 2, 3, 5, 8, 13, 20, 40 and 100, which is the sequence we recommend. The values represent the number of story points, ideal days, or other units in which the team estimates.