What is metrication???????

-Metrication refers to the introduction and use of the SI metric system, the international standard for physical measurements. This has involved a long process of independent and systematic conversions of countries from various local systems of weights and measures. Metrication began in France in the 1790s and spread widely during the following two centuries. The process is sometimes called metrification.



http://en.wikipedia.org/wiki/MetricationIt is the process of changing the values used in a system from imperial units to metric ones. I live in the UK and we used to use pounds and ounces, inches and feet etc but after metrication we use grams and kilograms and centimetres and metres.

It is practised because it is easier for two or more countries to trade if they deal in the same units, but also because the metric measurements are related to the SI (Systeme Internationale) and SI are almost always the measurements used in science and mathematics.
It is, as Wotnik and others have said here, the change from a local system of weights and measures to the metric system. However, Wotnik is slightly wrong about the status of the UK. We're neither fully metric nor fully Imperial here. In some areas of life - like weighing out loose goods in shops - we've gone metric. In other areas we've stayed Imperial - all of our road signs are in miles and yards, our draught beer and bottled milk are sold in pints and most Britons think of their height in feet and inches and their weight in stones (14lb) and pounds (unlike Americans, who just use pounds for their weight. In some areas, imperial units seem to be making a comeback: the major supermarket chain ASDA recently reintroduced 1-pound packs of strawberries after 16 years selling them in metric sizes. So we're a bilingual country as far as weights and measures are concerned.