Up into recently, when a pilot arrived in the cockpit of a typical airliner they were faced with dozens of big books that clutter the cockpit. On top of that, many of you probably seen pilots walking around the terminal with those big black suit cases. Well those suit cases are additional manuals that were required. They were navigation books, performances, & company manuals. In some cockpits there's so little space that crews had to put there bags in the cargo bin. Today, there are a number of airlines that are going electronic with these manuals. More airlines are issuing their crews with ipads for the cockpit, or sometimes its called an electronic flight bag or efb. The efb allows the airlines to store thousands of data or books into these efb saving lots of space n the cockpit & making the airplane lighter for greater fuel savings. If I had to guess, those books probably  weigh a thousand pounds. It's important to know the pilots will not be able to excess the internet or watch movies with these ipads. They will be restricted to doing weight & balance, aircraft performance data, & navigation. The airlines will keep one or two important manuals as back ups in the cockpit in case the efb goes out.