Answer to Question 1
The Interactive Mail Access Protocol (IMAP) performs the same basic functions as POP, but includes additional features. For example, IMAP can instruct the e-mail server to send only selected e-mail messages to the client instead of all messages. IMAP also allows the user to view only the header and the e-mail senders name before deciding to download the entire message, which avoids the POP requirement that users download e-mail messages to their computers before they can search, read, forward, delete, or reply to those messages.
IMAP lets users create and manipulate e-mail folders (also called mailboxes) and individual e-mail messages while the messages are still on the e-mail server; that is, the user does not need to download e-mail before working with it.
IMAP lets users manipulate and store their e-mail on the e-mail server and access it from any computer, which is important to people who access their email from different computers at different times. The main drawback to IMAP is that e-mail messages are stored on the server and, over time, can exceed the users space allowance on the server. In general, server computers use faster (and thus, more expensive) disk drives than desktop computers. Therefore, it is more expensive to provide disk storage space for large quantities of e-mail on a server computer than to provide that same disk space on users desktop computers.
Answer to Question 2
The worldwide growth in the number of mobile devices and the Internet of Things has consumed existing IPv4 addresses much faster than anyone had predicted and current estimates are that new IPv4 addresses will no longer be available as soon as 2015.
Evolution of the Sun's luminosity, radius and effective temperature compared to the present Sun
Hydronephrosis. Normal kidney (left) and kidney with hydronephrosis (right) are compared. Note the d
Urinalysis. During a simple urinalysis, a stick with colored blocks is dipped into a urine specimen.
The primate skull is generalized compared to many other mammals.
Embryos Compared
The adsorption spectrum of rhodopsin compared with the human scotopic spectral sensitivity curve.