- Mechanical devices - Vehicles - Clocks - Motors - Electronics - ICs - Discrete circuits - Complex circuits - Consumer electronics - Solid objects - Furniture - Chairs - Tables - Cupboards - Beds - ... - Buildings - Permanent buildings - Temporary buildings ------ Where do we put things like: - Screw - Television - Solar cooker - Railway segment - Rifle - Headphones - Backpack - CD-ROM - Mirror - Signpost - Decorative vase - Taj Mahal - Electricity distribution substation - Fishing net - Tractor