What is TCP/IP, BACnet, Lon N2 Bus and Lan? What are the differences between these automation protocols?

TCP/IP is  acommon communication channal or platform which all above protocall can be transmited via TCP/IP. 

Bacnet is a high speed trafic datta communication protocol which is havin higher band with supporting of most other control like HVAC,BMS,FACP,ACS,CCTV etc Applications.

Lon & N2 bus is locally network which local operating network to communicate between central server to remote distance system like HVAC,AHU,PUMP ontrol etc., communicate via power,RF, optical ETC

Lan local area network which are communicate with dedicated area of computer network via fiber, cables.

Diffrenses are Bacnet can adopt many network. But lon need its converter tool to communicate with other system. N2 bus is dedicated bus which can not take other signal without LON card support. Lan is no for automation purpose, which is for computer to computer conectivity.