Both pure and applied, the foundation of science is experimentation.

In March 2009, the Science Council, which represents professional scientific organisations in the UK, announced that after a year of consultation they had come up with an official definition of science. The definition was as follows:

"Science is the pursuit of knowledge and understanding of the natural and social world following a systematic methodology based on evidence."

Science is a system of acquiring knowledge through the development of ideas and theories which must then be supported by evidence, which in itself comes from the collection and creative interpretation of data. But science is also the organised body of knowledge the human race has acquired using this system.

Science can also be divided into pure science and applied science. The former is as described above; the latter is the application of research to human needs. Science divides further into natural science (the study of natural phenomena) and social science (the study of human behaviour and society). Within these divisions are many specialised fields of science with their own terminologies, methodologies, societies and journals, although there is frequently overlap between fields.

In Britain, most scientific research is carried out within universities, and is funded from several sources, including government, the private sector and various charities, of which the Wellcome Trust is the largest.

The beginnings of modern science can be traced back to the Scientific Revolution of the 16th and 17th centuries. It was in fact not one but a whole series of ideas that contributed to this revolution, overturning views held since antiquity. Medieval scientific philosophy was abandoned in favour of new methods proposed by Bacon, Galileo and Newton and there was an increased emphasis on the importance of experimentation and observation to test scientific theories. Mathematical models replaced abstract religious ideas as ways of explaining how the world worked. The pursuit of science for its own sake gained validity and new organizations were set up to study the natural world. The Royal Society of London was formally established in 1660, and its motto 'Nullius in verba', ('Take nobody's word for it'), epitomised the new enthusiasm for empirical scientific methods.

Many of the pioneers of the Scientific Revolution were British and, notwithstanding concerns about funding, Britain continues to have a highly innovative, world class scientific community. The UK is home to over seventy Nobel prizes in science; the most recent prize-winner Sir Martin Evans won, with two American colleagues, the 2007 Prize in Physiology or Medicine for their work on stem cells. The UK has some of the world's finest research facilities across a whole host of scientific fields. One third of the human genome map was produced in the UK, at the Wellcome-funded Sanger Institute outside Cambridge. Around 1600 scientists use ISIS, the world's brightest pulsed source of neutrons and muons, at the Rutherford Appleton Laboratory in Oxford. The Kew Millennium Seed Bank project aims to address the loss of the Earth's biodiversity by securing the future of all of the UK's native flowering plants and saving over 24 000 plant species from extinction worldwide.