instant messaging diagram
WHAT IS INSTANT MESSAGING ???
This is a form of real time communication between tro or more peole that enables them to have a "virtual" conversation. IM involves" talking" to someone in real time by typing and receiving messages.

It is popular because it allows:

• Quick and easy communication in real time
• People to work collaboratively and discuss their vies
• The user to see who is onlineand decide if the want to engage ina conversation- you able to set the status so tha people know if you are avaible to talk or busy
• use through ceratain mobile phones, PDAs and other portable devices.

DISADVANTAGES OF IM

 

• You need Internet access to use IM
• If the connection is slow, tjis could impact on the real time feature.
• Overuse of IM could result in less face-to-face contact with people.
• People may misunderstand information as it lacks emotion- to combat this, emoticons have been invented.
• if you use text language  regularly, it could affect your writing skills.
• You may prefer to chat rather than type a message.

 A VoIP diagram
WHAT IS A VOIP (VOICE INTERNET PROTOCOL)
This is similar to IM on a computer, but sound rather than text is sent. It is just like making a telephone call.
Ruby's friends were getting large phones bills using their mobiles, so the switched to suing VoIP.
They can use this feature when they have access to the Internet on their computers or in some cases on their mobiles. They  can now talk witout running up huge phone bills.
To use VoIP through a computer you need a headset or speakers and a microphone, and a webcam if you wish to stream video to the other caller. Mobile phones must have a 3G or mobile internet connection,if you are using a landline phone, it needs to be plugged into the Internet router.
Making calls this way is free, even international ones, but some VoIP service providers charge a membership or monthly fee.

DISADVANTAGE OF VOIP

• A slow Internet connection can cause  a delay in the sound begin received by the callers- this is known as latency and may spoil the experience. 
• VoIP will only work with an internet connection. If the Internet service provider (ISP) or the VoIP service provider is temporarily unavailable,then calls cannot be made.
• VoIP designed to be used from anywhere in the world. Users do not have a geographical telephone number, e.g, area code then numbe. When people dial 999 from a home phone or a mobile, the emergency services can track down the signal, but with VoIP this is not always possible and could be a problem