Definition of the term "Lattice of field extension"

Question

I was working on some field theory problems and I'm stuck at this particular point where a part of a question asks, "..... now draw the corresponding lattice of field extensions from $\mathbb{Q}$." I don't understand this specific question as in my text book I found no definition/information about this term "lattice of field extensions". I would be very happy if someone can explain this to me preferably with an example and how to "draw" these things.

Answer 1

See wikipedia for what lattice is (there are pictures there of diagrams as well). Field extensions are partially ordered by inclusion, and their "meet" is the intersection (intersections of field extensions of a fixed field are such a field extension again). The join is just the field generated by the union (all within some algebraic closure).

For an example, see this question.

Also see the examples here, as well.