Internet and Email: Protocols, Ports and Terms

The correct answer is B, Trash. When a letter is deleted from a mailbox it is not wiped out at once. It is moved to a folder called Trash, or Bin in some services, and kept there for a fixed number of days so that a letter deleted by mistake can be restored. Only when the folder is emptied, or the holding period ends, is the letter removed for good.

Option A, Drafts, holds letters that have been written but not yet sent, so a deleted letter never lands there. Option C, Inbox, is the folder where arriving mail is kept, and deleting a letter is precisely the act of taking it out of the Inbox. Option D, Sent mail, keeps copies of the letters you have already despatched, which is a record of outgoing post and not of deleted post. Trash is therefore the only correct choice.

The correct answer is B, To. The To field of a mail window is meant for the addresses of the people the letter is written to. More than one address can be typed there, separated by commas, and every recipient can see the whole list. Copies can also be sent through the Cc field, which all recipients see, or the Bcc field, which no other recipient sees.

Option A, Subject, is the one-line heading that tells the reader what the letter is about, and an address typed there would never be treated as a destination. Option C, Message, is the body of the letter, where the matter is written. Option D, From, shows the sender's own address and is filled in automatically by the mail service, so it names the writer and not the reader. Hence only the To field carries the recipients' addresses.

The correct answer is B, 1969. ARPANET was funded by the Advanced Research Projects Agency of the United States Department of Defense, and in 1969 it linked computers at four American universities and passed its first message between them. That experiment proved that packets could be switched between distant machines and grew into the internet.

Option A, 1959, is too early: the packet-switching idea had not yet been worked out and no such network existed. Option C, 1979, falls well after ARPANET was working and is remembered instead for early newsgroups. Option D, 1989, is the year Tim Berners-Lee proposed the World Wide Web at CERN, which is a service on the internet and not the network itself; papers often place 1989 as a distractor for exactly this reason. Remember the pair 1969 for ARPANET and 1989 for the Web.

The correct answer is C, Tim Berners-Lee. Working at CERN in Switzerland, he proposed a system of linked documents in 1989, wrote the first browser and server, and put the first website online in 1991. HTML, HTTP and the URL all come from his design, which is why he is called the inventor of the World Wide Web.

Option A, Vinton Cerf, designed the TCP/IP protocol suite along with Robert Kahn and is called a father of the internet, which is the network rather than the web. Option B, Charles Babbage, belongs to the nineteenth century and is the father of the computer for his Difference and Analytical Engines. Option D, Ray Tomlinson, sent the first network email in 1971 and chose the @ sign for addresses. Each of the three is famous, but only Berners-Lee is tied to the Web.

The correct answer is C, the @ sign. Ray Tomlinson sent the first message between two computers on ARPANET in 1971 and needed a character that would never appear in a person's name. He picked @, which already meant at in trade bills, so that an address could be read as a user at a place. Every email address since then has the form user@domain.

Option A, the hash, is used to mark tags on social sites and as a comment sign in some programs, never as the divider in a mail address. Option B, the ampersand, means and and is used in program names and file paths. Option D, the asterisk, works as a wild card in searches and as the multiplication sign in spreadsheets and programming. Only @ separates the two halves of an email address.

The correct answer is D, 443. HTTPS is HTTP wrapped in encryption, and web servers listen for it on port 443. When an address begins with https, the browser opens a secure channel on that port, and the padlock shown beside the address means the traffic on it is coded.

Option A, 21, belongs to FTP, the File Transfer Protocol, which uses port 21 for commands and port 20 for the data itself. Option B, 80, is the default port of plain HTTP, the unencrypted form, and is the most tempting distractor because the two protocols do the same work. Option C, 110, is the port of POP3, which downloads incoming mail from a server. Keeping the set 80 for HTTP, 443 for HTTPS, 21 for FTP and 110 for POP3 in mind answers most port questions in one stroke.

The correct answer is C, Bcc. Bcc stands for blind carbon copy. An address typed there receives the letter, but it is hidden from everyone else on the list, and the people in Bcc cannot see one another either. Offices use it to circulate a notice to many people without exposing their addresses.

Option A, To, holds the main recipients, and every address in it is visible to all. Option B, Cc, stands for carbon copy and sends a copy for information, but those addresses are shown to everyone, which is exactly the difference the question is testing. Option D, Subject, is the heading of the letter and carries no address at all. Learn the pair together: Cc is an open copy and Bcc is a hidden copy.

The correct answer is C, 128 bits. IPv6 was framed because the older scheme was running out of addresses, and its 128-bit length yields a pool so large that shortage is no longer a worry. Such an address is written as eight groups of hexadecimal digits separated by colons.

Option A, 32 bits, is the length of an IPv4 address, written as four decimal numbers from 0 to 255 separated by dots, and it is the distractor most often marked by mistake. Option B, 64 bits, is not the size of any IP address; it describes processor and register widths. Option D, 256 bits, is a length met in encryption keys such as AES-256, not in addressing. So remember the pair: IPv4 is 32 bits and IPv6 is 128 bits, four times as long.

The correct answer is A, SMTP. SMTP stands for Simple Mail Transfer Protocol and is the rule set that pushes a letter out of your mail program to the server and onward from one server to the next until it reaches the receiver's mailbox. Its usual port is 25.

Option B, POP3, the Post Office Protocol version 3, works in the other direction: it downloads arriving mail to one device and normally deletes it from the server. Option C, IMAP, the Internet Message Access Protocol, also handles incoming mail, but it keeps the letters on the server so the same mailbox appears alike on every device. Option D, FTP, is the File Transfer Protocol and moves files between a computer and a server without any connection to mail. Sending is SMTP; receiving is POP3 or IMAP.

The correct answer is A, DNS. The Domain Name System is the directory of the internet. People remember names, while machines route traffic by numbers, so a DNS server looks up the name typed in the browser and returns the matching IP address before the page is fetched. It listens on port 53.

Option B, DHCP, the Dynamic Host Configuration Protocol, hands out an IP address to a machine when it joins a network; it allots addresses instead of translating names. Option C, HTTP, carries the page once the address is known and does no translation. Option D, URL, the Uniform Resource Locator, is the written address of a page and contains the domain name, but it is a form of address, not the service that resolves one. Only DNS does the conversion.

The correct answer is B, a government body. The last part of a domain name is the top-level domain and tells you the kind of owner. Government offices use .gov, often with the country code added, as in india.gov.in for the National Portal of India.

Option A is wrong because commercial firms use .com, which stands for commercial and is the commonest domain on the web. Option C is wrong because educational institutions use .edu, and in India colleges and universities generally use ac.in for the same purpose. Option D is wrong because network providers use .net. Two more are worth remembering with these: .org for non-profit organisations and .mil for military establishments. Reading the tail of the address therefore tells a candidate at once what sort of body runs the site.

The correct answer is C, FTP. FTP stands for File Transfer Protocol. It opens two channels with a server, one on port 21 for commands and one on port 20 for the matter itself, and moves whole files in either direction, which is how web pages are put on a hosting server.

Option A, SMTP, carries outgoing email and can send a file only as an attachment to a letter, not as a plain transfer. Option B, Telnet, lets a user log in to a distant computer and type commands on it through port 23; it gives control of the machine but does not itself move files. Option D, IMAP, is a mail-reading protocol that keeps letters on the server. For pure file transfer the answer is always FTP, or its secure forms FTPS and SFTP.