Is Angularjs Clientside or Serverside or Both
It is purely client side.
If server side how can we connect to databases.
You either use a client side database or you get the data from the server using an appropriate protocol (typically this would be a web service accessed via Ajax).
if not used in server side which one is better php or nodejs..( i need to design a website which uses huge data and bandwidth..)
"Better" without lots of measurable requirements is highly subjective.
Angular JS is a client side JavaScript framework for data binding. etc..
You can use Node JS for your server side operations along with Angular JS.
or Any other server side languages like PHP, Java, Etc...