A paper shredder is an equipment that cuts paper up into strips or fine particles. Shredders are used mainly by government offices, businesses and private persons to destroy their respective documents which are considered to be very confidential, private and sensitive.

In the past, the United States Embassy in the country of Iran minimized and destroyed important papers and documents by using a strip-cut paper shredder prior to the embassy take-over in 1979. Generally, the use of paper shredding machines was scarce for most non-government offices. However, after the Supreme Court of the United States decided that the Fourth Amendment does not forbid search and seizure of trash or garbage left for collection or pick-up without a warrant. Paper shredding machines gained popularity amongst US citizens who want to safeguard their privacy. Greater demands for said equipment increased due to landfill concerns, identity theft, anti-burning laws and industrial espionage.

Shredders come in various types, sizes and price depending on the need for cutting a few pages or for tearing millions of documents. A normal or ordinary paper shredder is powered by electricity; the ones that are not power-driven by electricity consist of a special kind of scissors which has multiple blade pairs and shredders that are manipulated by the hand. The classification of these machines depends primarily on the size and shape they generate.

The least secure is the strip-cut shredder which employs knives that rotate to cut strips that are narrow, and which are as long as the original sheet of the paper being shredded. The resulting strips from this type of shredder can be reassembled by a patient and unwavering opponent or rival; since the shredded form is not very randomized. Further, a lot of waste is likewise generated from this kind of shredder since the chad is not compressed and possesses a large surface area.

Confetti-cut or cross-cut shredders utilize two contra-rotating drums to sever the paper into diamond-shapes, lozenge shapes, parallelogram and rectangular shreds. The particle-cut shredder produces circular and tiny square pieces. Granulators and disintegrators continuously cut papers in an unsystematic manner till the particles are sufficiently tiny to pass through a mesh; while the Hammermills pound paper through a screen. The Pierce and Tear Rotating blade on the other hand puncture the paper then tears it apart, while the Grinders, which have a rotating shaft with cutting blades, break up paper until they are tiny or small enough to pass through a screen.

An innovative paper shredder must feature safety, efficiency and convenient characteristics that are generally jam proof, has safety sensors, has noise reduction, is energy-saving and cuts back on the production of mess.