Computer Internet Questions and Answers

Answer: D

Correct answer: SMTP

SMTP, the Simple Mail Transfer Protocol, is used to send mail - from a client to its server, and from server to server across the internet. The retrieval protocols are different, and the pair is worth distinguishing. POP3 downloads messages to one device and by default removes them from the server, which suits a single machine. IMAP leaves messages on the server and synchronises state - read, filed, deleted - across every device, which is why it is the standard for anyone reading mail on both a phone and a computer. The mnemonic is that SMTP sends and the others fetch. SMTP was designed without authentication, which is the root of the spam problem; the modern remedies are authenticated submission on port 587 and the sender-verification schemes SPF, DKIM and DMARC. FTP transfers files and has nothing to do with mail.

Answer: D

Correct answer: To allow page headers and footers to appear on document when it is printed

A header or footer is a page feature: what is placed there repeats on every page and is printed with it. That is what distinguishes it from ordinary text typed at the top of the first page.

Answer: C

Correct answer: Tele-conferencing

Teleconferencing is a meeting held between people in different places, connected by voice or video - an electronic meeting. Tele-shopping and tele-banking are transactions rather than meetings.

Answer: C

Correct answer: Copies of previously downloaded page resources, to avoid fetching them again

The cache holds copies of resources already downloaded - images, stylesheets, scripts, sometimes whole pages - so that a return visit can use the local copy instead of fetching it again. The benefit is speed and reduced data use, since the largest parts of a page are usually the ones that change least. Servers control it through HTTP headers giving each resource an expiry time or a validation token, so the browser can ask whether its copy is still current without downloading the whole thing. Its familiar drawback is staleness: a site updated on the server may still show the old version locally, which is why a forced reload - Ctrl + F5 - bypasses the cache. It should not be confused with the neighbouring stores the browser keeps: history lists pages visited, cookies hold site data, and the password manager holds credentials, encrypted rather than in plain text.

Answer: C

Correct answer: IMAP keeps messages on the server while POP3 downloads and usually removes them

Because IMAP leaves the mailbox on the server, the same account looks identical from a phone, a laptop and a browser. POP3 pulls messages down to one machine, which suits a single device but makes synchronisation awkward.

Answer: A

Correct answer: multiplexor

A multiplexor combines several lower-rate streams onto one higher-rate line and separates them again at the far end. A bridge and a router forward traffic rather than combining channels.

Answer: B

Correct answer: Data, segment, packet, frame, bit

Encapsulation adds a header at each layer going down the stack: the application's data becomes a segment at the transport layer, a packet at the network layer, a frame at the data link layer, and finally bits on the wire.

Answer: C

Correct answer: Bus

In a bus every station taps into one shared cable, so a break in it divides or disables the whole segment. A star gives each node its own cable, and a ring or mesh can often route around a failure.

Answer: C

Correct answer: Network

The server and the machines it serves are joined by a network; the clients are what it serves rather than what connects them.

Answer: A

Correct answer: ARPANET

ARPANET adopted TCP/IP on 1 January 1983, which is the moment the internet as a protocol family begins. The internet grew out of ARPANET rather than preceding it.