When using a wireless network the system tells me packets sent and received. What’s a packet?
It’s the size of a chunk of data in a TCP/IP network. It has the same meaning for wired or wireless. http://computer.howstuffworks.com/question525.htm
A “packet” in data terms is merely a conveniently packaged group of data.
Computer communicate in ones and zeroes. Without packets a stream of data might look like:
11001010001001001111100101110011100110001110111000111010011110100
This data stream needs to be broken up so the computer knows where one relvant byte stops and another starts. This division is called a packet.
A packet may also include other information such as its source, destination, size, error correction and so on. This data is kept in a header and/or footer on the packet to distinguish it from the actual data. All of this aids in the packet reaching its destination intact (for instance if there is an error the system knows to resend the packet).
Different communications protocols structure packets differently and I am not sure if wireless protocols add anything to the packet over what TCP/IP (the most common protocol) uses but that is the gist of it.
Whenever you request something over the internet, the packets themselves don’t necessarily have to follow the same path or arrive in sequential order. The packet contain the information to be reassembled into a web page, e-mail message or files. Some packets may get lost somewhere over the network and you computer will send a message for it to be resent. It is a pretty amazing thing and it happens so fast that it isn’t intuitive that is what is happening.
About how big is a packet?
Packets are as big as they need to be, up to a maximum size that depends on the protocol being used. The max for TCP/IP is about 1500 bytes.