Cabinet hardware includes hinges, latches, drawer rails, knobs and pulls (handles). Hinges can be exposed or concealed. Modern hinges add the ability of a soft close. Soft closing hinges are not surface mounted, they are installed inside of a dado cut. If you want to convert your exposed hinges to concealed you will need to reface your cabinets.
Traditional style for hardware call for knobs to be placed on doors and pulls to be placed on drawers. Now it acceptable to have all pulls or all knobs or any combination. Pulls can be placed on doors vertically or on a 45 degree angle (less common).
One common question regarding painting cabinets that have exposed hinges is what color should they be. The current trend for modern kitchens is to paint the cabinets white. If you are updating the knobs or handles to something currently popular like brushed nickel, it is recommended that you just paint your existing hinges to match the cabinets. For a more traditional or rustic style, you can match the hinges with the knobs and handles. All hardware that will not be painted should be removed before painting.