As same as most other travel cards in your own country, IC card allows you to charge, and use it widely on most transports such as trains, buses, ferries and some taxis.
You can also use an IC card as e-money to pay at vending machines, coin lockers, convenience stores, restaurants and many other services. As long as you see the respective IC card logo, you may pay with your card to go. It saves you from the trouble of finding coins when travelling to Japan.
Where to Get an IC Card
There are indeed some collectors who are fond of collecting IC cards from different regions, as they all come in a unique design with their cute characters. Among all, the Suica card is accepted in most places, including Osaka, Tokyo, some transportation systems in Hokkaido and Kyushu etc.. You can purchase one in major JR EAST stations at Multifunction Ticket Vending Machines or JR Ticket Offices. When you refund the card, the deposit of 500 yen and the remaining amount will be returned to you.