The Investment Association sectors divide up over 3,000 of the funds available in the UK, including some offshore (EU) funds, into smaller groups. The attached chart shows how the sectors fit together. It should help you to understand the broad focus of different groups of funds, such as whether they aim to produce income or capital growth. Many of the sectors also have a geographic focus.
Offshore funds have been admitted to Investment Association sectors since April 2010 (other than Absolute Return funds, which have been admitted since April 2008). Offshore funds are flagged in data for Investment Association sectors so that they may easily be identified.