Simple Mail Transfer Protocol (SMTP) is an Internet standard for electronic mail (email) transmission. First defined by RFC 821 in 1982, it was last updated in 2008 with the Extended SMTP additions by RFC 5321—which is the protocol in widespread use today. SMTPby default uses TCP port 25. Although electronic mail servers and other mail transfer agents use SMTP to send and receive mail messages, user-level client mail applications typically use SMTP only for sending messages to a mail server for relaying. For retrieving messages, client applications usually use either POP3 or IMAP.

Wi-Fi allows you to connect several computers at once, anywhere in the house - or if you have a laptop, to even use your computer in the garden. You don’t need to install extra phone lines or cables.
Wi-Fi creates a network in your home or office – a little zone where computers can get broadband internet. It uses radio waves, just like TV or mobile phones. You may sometimes hear this zone referred to as a WLAN (Wireless Local Area Network).

A device called a wireless transmitter receives information from the internet via your broadband connection. The transmitter converts the information into a radio signal and sends it.

You could think of the transmitter as a mini radio station, broadcasting signals sent from the internet. The ‘audience’ for these transmissions is the computer (or computers, as more than one can connect at the same time) which receives the radio signal via something called a wireless adapter.

The whole process, meanwhile, works in reverse, with the computer sending information to the wireless transmitter. It then converts them and sends them via your broadband connection.
To use Wi-Fi you will need certain equipment:

You may find that you already have a Wi-Fi network, as many ISPs (internet service providers) are setting up new customers with Wi-Fi from the outset.

If not, you could call your ISP and ask to upgrade. They might even upgrade you for free - and send you some or all of the equipment. If not, you might consider checking whether other ISPs are offering Wi-Fi to new customers.

In any case, you can buy the equipment yourself and set up your own Wi-Fi network using your existing broadband connection.

Many ISPs will supply you with a router, modem and wireless transmitter combined in one device, which it calls ‘the router’. To make your Wi-Fi set-up as simple as possible, you should consider using a similar device.

The router plugs directly into a phone socket and doesn’t need a computer to run it, so you don’t have to set up your computer next to the router.

Computers – mainly laptops – increasingly have built-in Wi-Fi receivers. If not, the simplest method of installing a receiver is a dongle - a little device that plugs into a USB port and transmits between your PC and wireless router.