What all can be done using wireshark??

Question

a less technical explanation on wireshark as I am new to networking and packet sniffing

Answer 1

is any kind of decoder needed? to decode the packets?

Answer 2

wireshark is a network protocol analyzer it helps you see the traffic on any chosen network interface. example if you run wireshark on your router you can see all the traffic that comes in and out of your whole network. if it's not encrypted you can even see it in plain text. you can see the visited websites .....
* (you can run wireshark on your router if you flash a custom firmware like openwrt)

Answer 3

nop, wireshark has everything you need .
you can view them in ascii string mode and other modes.