The investment sector and associated companies of team members under funds (VC, PE, Angels) are curated from the Companies database.
For example -
A is working for fund XYZ and is involved in its investment. XYZ invests in Company Hector, which is in the fintech sector. Hence, A is associated with Hector and the fintech sector.
If A is a board member of Hector, then also she will be associated with Hector and the fintech sector.
Note that Board membership information is curated for selected geographies only. Refer Which geographies are board members available for?