a. LAN : Local Area Network
b. MAN : Metropolitan Area Network
c. WAN : Wide Area Network
d. Wi-Fi : Wireless Fidelity
e. NIC: Network Interface Card
f. VoIP : Voice Over Internet Protocol
g. UTP : Unshielded Twisted Pair
h. Modem : Modulator Demodulator
i. PPP : Point to Point Protocol
j. NOS: Network Operating System
k. SMTP : Simple Mail Transfer Protocol
l. IMAP : Internet Message Access Protocol
m. NNTP : Network News Transfer Protocol
n. NetBEUI: Network Bios extended User Interface
o. NCP : Network Control Protocol
p. BNC: British Naval Connector/Bayonet Naur Connector
q. GPS : Global Positioning System
r. MAC: Media Access Control
p. OFDM : Orthogonal Frequency Division Multiplexing
q. STP : Shielded Twisted Pair
r. SMTP : Simple Mail Transfer Protocol
s. FTP : File Transger Protocol
t. HTTP : HyperText Transfer Protocol
u. POP : Post Office Protocol
v. IPX/SPX : Internetwork Packet eXchange/Sequence Packet eXchange
w. Mbps : Mega bits per second
If you have any doubt, let me know...