In Emacs, can we maximize current active window, and then restore it back in multiple window environment?

More or less - try using winner-mode. It will remember the last few (ca 200) window configurations, and will let you walk through them with a simple (C-c (right|left)) keystroke. And it's quite easy to turn on, since it's built in:

(when (fboundp 'winner-mode)
  (winner-mode 1))

Combine it with windmove and moving between your windows will be even more awesome.

Use the command window-configuration-to-register: M-x window-configuration-to-register, press the Enter key, then some register (character), e.g. a. To maximize current window, use C-x 1. When you want to restore, type C-x r j a.