Join two lists with different types join d in departments on e.Department equals d.Name?

Short answer: var result = from e in employees select new { e.Name, DeptLocation = d.Location };

Example code

var result = from e in employees
select new { e.Name, DeptLocation = d.Location };

Real-world example (ShopNest)

A sales report joins orders and customers, then GroupBy(c => c.City) to show revenue per city.

Say this in the interview

1. Define — one clear sentence (the short answer above).
2. Example — relate it to a project like ShopNest or your real work.
3. Trade-off — when you would not use it.