Difference Between EtherChannel and Link Aggregation

Link aggregation (LAG) is simply a means to bundle multiple ethernet connections between a pair of switches to share the load. EtherChannel is Cisco's pre-standards model for doing so, which was originally inherited from the Kalpana acquisition. IEEE 802.3ad describes the standard way to aggregate links, including the Link Aggregation Control Protocol (LACP).

Link aggregation (LAG) is a partial implementation of the 802.3ad port aggregation standard. It bundles all of the controller’s distribution system ports into a single 802.3ad port channel, thereby reducing the number of IP addresses needed to configure the ports on your controller. When LAG is enabled, the system dynamically manages port redundancy and load balances access points transparently to the user.