Who employs school teachers?
Schools in the UK can be classified on two dimensions: the age range of the pupils and whether the school is in the maintained or the independent sector.
The age range can be thought of broadly as either primary or secondary. "Primary" normally means up to age 11, and primary teachers usually remain with their classes over the whole range of subjects. "Secondary" normally means from age 11 to 18, and the work of secondary teachers is subject-specific. However, there are increasingly many variations on these themes, and a tendency to blur the edges. An important example is that, in many areas, schools offering secondary education teach up to age 16 - which is of course the age up to which school attendance is compulsory - with education from 16 to 18 provided by what are often called sixth form colleges. Sometimes these colleges go even further, providing a variety of post-18 qualifications and adult education as well as teaching 16 - 18 year olds; such colleges are often called tertiary colleges.
The maintained sector consists of schools and colleges operated by local authorities or funded directly by central government. Parents do not pay fees. More than 90% of pupils are educated in the maintained sector. A teacher in the maintained sector would be most likely to work in a comprehensive school, one having pupils from right across the ability range. There are however a few areas of the country with a selective school system in the maintained sector, with selection by ability.
In the independent sector parents pay fees: from about £5000 per year in day schools, but substantially more in some parts of the country and in boarding schools. This income that independent schools enjoy is substantially greater than the funding per pupil in the maintained sector. Consequently facilities in independent schools are often better, as are salaries. Many independent schools select pupils by academic ability. For some teachers the prospect of working with the most able is very appealing, but others dislike the principle of selection by ability and prefer the challenge of teaching and motivating pupils of all abilities.
We should also mention that there is a range of special schools such as those dedicated to teaching the blind. If you feel particularly attracted to teaching in environments such as these, you will be able to find opportunities to do so.