A professional painter may also be called a house painter or decorator. This is a tradesman responsible for the painting and decorating of the inside and outside of buildings. For professional painters, the majority of their time is spent in preparation for paint application, not in painting per se. Cleaning and sanding surfaces, taping and applying paper or plastic to surfaces not to be painted typically involve 50% or more of the painter\'s total time budget. Although the brush and the fabric roller were the tools most readily associated with the painter, foam brushes are now commonly used for precise work requiring a straight line. Foam brushes can also be used to create a smoother surface using less paint that dries more quickly than brush applications. Like fabric rollers, foam rollers can also create patterns in the painted surface. Foam rollers are available in a variety of professional materials for high-quality applications. Cambridge is a university town and the administrative centre of the county of Cambridgeshire, England. It lies in East Anglia about 50 miles (80 km) north-by-east of London. Cambridge is at the heart of the high-technology centre known as Silicon Fen – a play on Silicon Valley and the fens surrounding the city. Cambridge is well known as the home of the University of Cambridge. The university includes the renowned Cavendish Laboratory, King\'s College Chapel, and the Cambridge University Library. The Cambridge skyline is dominated by the last two buildings, along with the chimney of Addenbrooke\'s Hospital in the far south of the city and St John\'s College Chapel tower in the north. According to the United Kingdom Census 2001, the city\'s population was 108,863, which included 22,153 students, and the population of the urban area (including the neighbouring South Cambridgeshire district) is estimated to be 130,000. Settlements have existed in the area since before the Roman Empire. A skilled professional is a person who is paid to undertake a specialised or highly skilled task or occupation. Traditional examples of professions included medicine, nursing, law and engineering but is now more widely used to include estate agents, surveyors , environmental scientists, forensic scientists and many more. It is also used in sport to differentiate amateur players from those paid for their work. Hence Professional footballer or Professional golfer. In some cultures the term is used as shorthand to describe a particular social stratum of well educated, mostly salaried workers, who enjoy considerable work autonomy, a comfortable salary, and are commonly engaged in creative and intellectually challenging work.Less technically, it may also refer to a person having impressive competence in a particular activity. Skilled professionals have expert and specialized knowledge as well as excellent manual and practical skills in their chosen field.