A wide variety of communication systems are used...
E-mail messages are text-based, but other types of file can also be sent as ‘attachments’.
E-mails that are received wait in a user's inbox until the user is ready to read them. (Unlike a telephone call, the user is free to ignore e-mails until they have time to deal with them.)
An e-mail message usually has the following parts:
|To||The address(es) of the person who the message is for|
|Subject||A short sentance describing what the message is about|
|Message||The text of the message. This can be as long as you like|
|CC||The address(es) of people to copy the e-mail to (Carbon Copy)|
|BCC||The address(es) of people to copy the e-mail to without anyone else knowing (Blind Carbon Copy)|
|Attachments||Files linked to the message (images, documents, etc.)|
A video-conference involves people sitting in front of a camera and a microphone, whilst watching other people of a screen and listening to them through loudspeakers.
Note: The camera is usually TV quality - much better than a standard webcam.
- Video camera
- High-speed network / Internet connection
- No travel costs
- No time wasted travelling to other cities / countries
- Can organise meetings at short notice
- Less personal than face-to-face meetings
- Documents (e.g. contracts) cannot be signed
Modern smart-phones can perform a wide variety of tasks:
- Make and receive telephone calls just about anywhere
- Send a receive SMS (short message service) messages
- Send and receive e-mail
- Send and receive files such as images, text documents, etc.
- Edit documents
- Most people would be lost without their mobile phone!
- Workers never get a chance to 'switch off' since they can always be contacted - can be stressful
- Mobiles are easy to lose, and often contain a lot of personal and/or business information. A lost mobile could be embarrassing / damaging if the wrong people got hold of it
Internet Telephony / Voice Over IP (VOIP)
Instead of using the normal telephone network (designed to carry voices using analogue signals), VOIP systems send voices through the Internet as digital data, just like any other Internet data (e.g. e-mails, files, webpages, etc.)
In other words, VOIP systems use your Internet connection to send and receive phone calls.
- VOIP software can be installed on a computer. Calls are then made using a headset (headphones / microphone) or by using a special USB handset (looks just like a normal phone)
- Special VOIP telephones can be plugged directly into the network (or can connect wirelessly using WiFi)
- No telephone line is required
- Call costs are very low, especially for long-distance calls
- Can include video
- Require special hardware and an Internet connection
- Not as reliable as normal phones, so cannot be relied upon for emergency calls (911, or 999)
- Call quality depends on the speed of the Internet connection
A fax machine is a device that can send a copy of a paper document over the telephone network.
- The sending fax converts the light/dark areas of the printed document into noises.
- These noises travel through the phone system and are received by another fax machine.
- The receiving fax machine converts the noises into printed marks on a piece of paper - making a copy of the original document.
- Low quality - images are especially poor
- Slow to send (compared to e-mail)
One reason that faxes are still used is that most businesses would accept a document such as a contract that had been signed, and sent by fax. (Electronically signing e-mail attachments is not yet widespread.)