Hi friend!
The most different is that VPWS is used on point to point (P2P), the VPLS used on point to multipoint (P2MP). They are both L2VPN services.
Virtual Private Line Service (VPWS) - VPWS virtualizes private lines only between two locations. Examples of VPWS services include IP/based Frame Relay, ATM, and Ethernet services.
It is also known as ETHo (Ethernet on) or VLL (Virtual Private Line).
Virtual Private Local Area Service (VPLS) - VPLS virtualizes local areas between multiple locations. This is basically a method of Ethernet-based multipoint-to-multipoint communication over IP or networks.
Compared with VPWS and VPLS, VPLS has more advantages.