E - F
An email spoof is a bogus email that appears to originate from a legitimate source. A spoofed email will appear to come from a trusted domain (for example, John.Doe@yourbank.com) when in fact it was sent from the server of a spammer.
The process of encryption can take on many forms. However, its sole purpose is to mask or disguise sensitive data in preparation for transferring it through an unsecured medium (whether that’s hard-wired or wireless). Once the data reaches its intended destination, it is usually decrypted back into its original form so that it can be read.
Extensible Authentication Protocol is an authentication protocol used in both wired and wireless environments as a security check between a client and a server. EAP is compatible with other authentication protocols and acts like a “city bus" that can transport other authentication commands to and from clients and servers.
A filter does just that, it filters unwanted information by comparing an incoming data stream against some type of model and rejects the data that does not match. This is essentially how an email spam filter works.
A firewall is a security measure that controls the flow of data in and out of a private network. The primary purpose of a firewall is to protect a computer or network by regulating data traffic. A firewall can be software driven (like Windows Firewall) or it can be a hardware device. Some modern day routers have firewalls built into them.
A hard drive becomes fragmented when a data string has to be broken up into multiple pieces in order to fit on the drive. Think of your hard drive as a pie chart with each piece of pie representing a segment on the hard drive platters. If there are no segments large enough to fit the entire data string being written, the drive puts the data wherever it can find space. With data strings spread out in this manner, it takes the drive longer to find the information and reassemble it. While this is not necessarily a security risk, fragmentation does shorten the lifespan of a hard drive and can adversely affect system performance.