anitha1991 :
what is public ip and local ip??
Public IP is the IP address that the outside world sees. For example, if you go to Google and type "my ip", it will tell you your public IP.
Local IP is the IP address that identifies your computer within your network. It starts with 192.168.x.y where x and y are some numbers.
anitha1991 :
does ip change when i use free wifi??
Your local IP, maybe. Your public IP, no.
anitha1991 :
then what will happen i use pc with wifi modem??
You get both wired connection and wireless connection. I am not sure what you are trying to ask here. But a wireless modem is not better than a non-wireless modem + router combo.
anitha1991 :
does ip change at tat time?
At what time? Your public IP is managed by your ISP (Internet Service Provider). Your public IP will not change unless your ISP changes it. You use a proxy to mask your public IP for browsing or for some other connection. This is generally more trouble than it's worth unless you have a good reason for masking your public IP.
You can change your Local IP to whatever you want.