What three metrics are used to define consistent network application availability

Whats three fourths of 15(this is supposed to be in math but i clicked too fast)

Explain how email technologies enable the exchange of messages between users. find out the typical parts of an email address and explain each part.

What is transmission control protocol/internet protocol (tcp/ip)? software that prevents direct communication between a sending and receiving computer and is used to monitor packets for security reasons a standard that specifies the format of data as well as the rules to be followed during transmission a simple network protocol that allows the transfer of files between two computers on the internet a standard internet protocol that provides the technical foundation for the public internet as well as for large numbers of private networks