A 2,3 or 4 way (co, tri, quad-axial)l speaker is a speaker with two, three or four built in components. A component speaker set contains individual units that each provide either a specific direction or frequency of sound. For example, a tweeter, mid-range speaker and sub-woofer would all be separate components within the set would be a tri-axial or 3-way set of speakers.
2-way (co-axial) contains a mid-range cone in addition to a tweeter (2 components) cone for high-frequency sound
4-way (quad-axial) has a bass and mid-range cone as well as two tweeters (4 components). The extra tweeter gives these speaker better high-range sound.