A "laminate" is a structure made up of layers of one or more materials, tightly bonded together so as to create something with enhanced properties - greater than the sum of the materials. Plywood is a laminate; there are many examples. The particular version of interest here is that in which various more-or-less flat materials - papers or pictures or the like - are encased in a transparent plastic medium which is sealed around them or bonded to them. The machine that does this is called, obviously, a "laminator". The document (or whatever) is fed into the machine, which pulls it through using rollers and applies the film.
There are two processes of lamination; hot and cold. Cold laminators (also known as tape laminators) use pressure to do the job: hot laminators use heat to seal the film.
Cold/Tape Laminators: the film comes in a sticky state. Tape is supplied in rolls which are fed to both edges of the film, between the upper and lower ones: the rollers, while pulling the films through, by their pressure seal the film onto the tape. Cold/tape laminators come in purely manual models, requiring no power, and electrically-driven versions.
Hot laminators: come in three versions: pouch, roll, and dry-mount. All are electrically-driven.
Pouch laminators: seals the material in a bag or pouch. Only the edges of the pouch are actually sealed by the heat, therefore this is the type used when documents or photos are to be protected but not actually bonded to the film. The edge can be adjusted as closely as desired to the edge of the document so that it doesn't move around within the pouch, once sealed. ID badges typically use this type. They are good for documents up to 20" wide depending on the make and model.
Roll laminators: a continuous roll of film is sealed to the material. Film can come in rolls up to 1000' in length and up to 60" wide. In high-volume environments, the configuration of the machine can vary drastically: the number of rollers, their type, heat control, cutting - all are subject to options. Some of them follow below.
Dry Mount: a document is to be placed on some material (the "substrate") and laminated but not to be covered by the film. In this case, a tissue adhesive is placed between the document and the substrate, and the whole sandwich is heated and pressurized for a set period of time: the adhesive saturates both the document and the substrate and creates a durable whole.
Variable temperature control: the heaters can be set as required to handle varying combinations of material and documents.
Cooling fans: as stated: used in high-volume environments to dissipate heat from the document as soon as possible - thus promoting curl-free and wrinkle-free results.
Cooling plates: serve the same functions as cooling fans, but absorb heat from the document as it passes out of the machine.
Heating: may be applied by platens, of varying capacity, or roller shoes, or even by the rollers.
Rollers: two-roller machines pull the document through the machine: it has to be inserted by hand until the roller grab it: they are at the ejection end of the machine so may be tricker to use. Four- or six- roller machines pull the document through smoothly and in correct alignment. Some machines use the rollers to apply the heat.
Pressure adjustment: to vary the pressure of the rollers depending on the material used and the nature of the documents. Most small machines are of the fixed-pressure and -temperature varieties.
Slitters: trim the laminate as it's ejected.
Variable speed control: as stated, to cope with the various materials and documents. On a fixed-temperature machine this can be used to effectively vary the heat: move more slowly, apply more heat; push it through faster, less heat is used.
There are many more terms that an expert may need to be fully conversant with his machines but the above should serve as an introduction for the user.