Remote is about being far away. Secluded is about being hidden away, and that can be just round the corner.
Both words suggest peace and quiet, which is why children swap them. The difference is whether the quiet comes from distance or from hiding.
Remote measures miles. A remote farm in the Scottish Highlands might be an hour's drive from the nearest shop, with a single-track road and no bus. It is hard to reach simply because it is so far from everything else.
Secluded measures privacy. A secluded bench behind the hedge at the back of the school field is only a minute from the classrooms, but nobody can see it and hardly anyone knows it is there. A secluded spot can be in the middle of a busy town.
Far away from towns and hard to reach.
Similar: distant, faraway, lonely
Quiet and hidden away from other people.
Similar: hidden, private, remote
Closest-meaning questions often put these two side by side. If the passage describes a hidden garden in the middle of a city, remote is the trap answer, because nothing about it is far away.
Definitions and example sentences on this page are the ones a child sees inside Wordrealm, taken from our list of over 1,100 words. It is free to browse, with nothing to sign up for.
Plain-English guides to each test, from the councils’ own pages: Kent Test · Medway Test · Bucks Secondary Transfer Test