What is EDCA (Enhanced distributed channel access)?

The contention based channel access technique called Enhanced Distributed Channel Access (EDCA) is considered as the mandatory mode for Medium Access Control (MAC) in IEEE 802.11e. The term EDCA is utilized in wireless organizations supporting the IEEE 802.11e Quality of Service upgrade.
It upholds separated and dispersed admittance to the Wireless Medium utilizing eight unique client priority sub fields supporting four Voice, Video, Best Effort and Background Access Categories.