A lock is a mechanical fastening device which may be used on a door, vehicle, or container, restricting access to the area or property enclosed. such as :

Lock pick , Mortice lock , Padlock , Bored cylindrical lock  ,  Combination , Pin tumbler  , Electronic  , Ignition  ,  Warded & Bike Locks , Cables & Chains , Combination Padlocks , Hasps , Keyed Padlocks ,  5 Lever Lock , Bicycle lock , Cam lock , Child safety lock , Combination lock , Cruciform (or Zeiss) lock ,  Cylinder lock , Deadbolt , Disc tumbler lock ,   Electronic lock , Electric strike , Magnetic lock , Keycard lock ,
Lever tumbler lock , Chubb detector lock , Protector lock ,  Magnetic keyed lock ,  Padlock ,  Pin tumbler lock ,  Rim lock ,  Tubular pin tumbler lock ,  Time lock ,  Turner lock ,  Wafer tumbler lock ,  Warded lock ,
Security door locks .

 Locks may be entirely mechanical, or electromechanical. They may be operated by turning some form of removable key, by keying or dialing in a combination which directly or via  electromechanical means .

A latch is a type of mechanical fastener that is used to join two (or more) objects  together   ranging in complexity from flexible one piece flat springs of metal or plastic,  to multi-point cammed latches used to keep large doors closed. A latch typically engages another piece of hardware  known as a keeper or strike.  
Slam latch: uses a spring and is activated by the shutting or slamming of a door. and is ideal for industrial, agricultural and construction applications  Other type of latches are :Spring , Passage/Privacy , Deadlatch , Deadbolt latch (Single throw bolt) , Slam ,Compression , Draw , Rotary  & Cam latches

 Brands
Alcatraz , Bell ,BisonLake , Boxer Tools , Bravo , CCL Security Products , Custom Accessories  ,GE Security, Gilmour, Hottestdealsever , IMPERIAL MFG GROUP , Import , Kaba Ilco , Kent, Knox , Kryptonite , KWIKSET , LANDMANN ,MAG ENGINEERING & MFG  , Master Lock, NATIONAL MFG CO , NUSET , Olympus , OnGuard ,  Panacea ,  PANTHER VISION , Pitbull , Planet Bike , PRIME LINE ,  Racor , Rutland , Safeskies Liberty Locks ,Samsonite , Schlage ,  Schwinn,, Sesamee, SEYMOUR MFG CO INC, ShurLok , STANLEY HARDWARE , SunLite , Thule ,  Trimax, UHP , USA Games Systems,  Winner International, Wordlock ,
Lock (device), a mechanical device a door or any other barrier closed.