What is meant by Blister packaging in medicines?

Blister pack is a term for several types of pre-formed plastic packaging used for small consumer goods, foods, and for pharmaceuticals. Blister packs are commonly used as unit-dose packaging for pharmaceutical tablets, capsules or lozenges. Blister packs can provide barrier protection for shelf life requirements, and a degree of tamper resistance.
The primary component of a blister pack is a cavity or pocket made from a formable web, usually a thermoformed plastic. This usually has a backing of paperboard or a lidding seal of aluminum foil or plastic. A blister that folds onto itself is often called a clamshell.
Blister packs are useful for protecting products against external factors, such as humidity and contamination for extended periods of time. Opaque blisters also protect light-sensitive products against UV rays. Blister packs are created by means of a form-fill-seal process at the pharmaceutical company or designated contract packer. A form-fill-seal process means that the blister pack is created from rolls of flat sheet or film, filled with the pharmaceutical product and closed (sealed) on the same equipment. Such equipment is called a blisterline. There are two types of blister machine' design: rotary and flat-plate.
Advantages of Blister Packaging

The first and foremost use of this sort of packaging is that it helps the patients follow the drug regimens. Drugs and medicine tend to have a longer life and more extended expiry date when this type of packaging is used. Another great benefit of this packaging is that there is a separate blister for each pill or capsule; the possibility of pills getting contaminated as a whole is entirely ruled out.
In this type of packaging, days of the week are incorporated on the sheet, so the patients have a better idea as to how often they are required to take their medication. Since aluminum sheets are used in the blister packaging, no type of contamination is possible but this has some costs too.