when we use a href tag for giving command to Bolt GPIO then are we using get request to perform digitalWrite function? and if so then to which server we are making this request?
Please elaborate as the question is not clear.
i am not clear about the format for calling of digitalWrite function(as used in arduino) through html
code line:
<button><a href="digitalWrite?pin=2&state=LOW"
are we making get request or building a query string through this line?
Hi,
You are requesting the server present on your Bolt device. This page has to be stored on bolt only the will it perform as required , it as if the server makes a request to itself in a way
hello thanks 
okay that is we are making esp8266 to work in server mode and the request is being made to wifi module and is processed by it?and in order to process every kind of get request there must coding done in esp module and saved to its firmware?
Yes, that is correct. The BOLT is running a server that handles the GET requests.