Email, an abbreviation of electronic-mail, can seem very mystical and confusing but it's one of the most powerful tools on the internet. Even people who don't use web sites are likely to have used email at some time in their lives.
With email you can write and send a letter and it can arrive in your recipient's mailbox in a matter of seconds. You can of course send text, but you can also send pictures, videos and all other computer files via email.
As long as you know someone's email address, it's possible to send that person an email. As long as someone knows your email address, that person can send you an email too.
Email is very important because it allows children to communicate with their friends, their teachers and people across the world from their computers.
Some schools let children email in their homework and some run twinning schemes with other schools across the world, encouraging children to send emails to each other about their lives.
While children rarely write letters any more, email is a wonderful opportunity to promote letter writing and the importance of literacy. This is especially important when children are emailing internationally with people who won't necessarily understand abbreviated (shortened) or colloquial (slang) English.
Message boards, forums or newsgroups are very much like email. The difference is that instead of sending to an individual you send your message to the message board for everyone to read.
Message boards can be public and open to everyone, or private where only invited people can read them. They are very useful for researching information as children can look at conversations between other people and then contribute their own comments or ask further questions to the message board users.
These messages can be published on the message board in a matter of seconds. Message boards can be moderated. This means someone reads all of the messages and removes or edits the unsuitable ones. All bbc.co.uk message boards are moderated.
Chat rooms let people talk amongst themselves in real-time. There are lots of general conversational chat rooms, but there are also topic-specific ones where you can talk with, or ask questions to, people with an interest or expertise in the topic.
Chat rooms can be fast and frantic and they're not always the best places for children to look for in-depth conversations or research. Chat rooms can be public or private and they can be available on websites or through computer programs. Chat rooms can also be available through online computer and video games.
Instant messages are like a chat room except the chat is always private and cannot be read by anyone not invited into the conversation.
Children should know the person who they are instant messaging and the recipient should know them too. Otherwise either party can choose to ignore the message and not start a conversation.
Instant messages can be used for having a more in-depth discussion with a friend or someone like-minded who has been met through a message board or in a chat room.
Instant messaging is usually available through computer programs, but it also can be available through websites and computer and video games.