linq find ids from one list in another list code example

Example 1: select from list where not in other list c#

var result = peopleList2.Where(p => peopleList1.All(p2 => p2.ID != p.ID));

Example 2: select from list where not in other list c#

var result = peopleList2.Where(p => !peopleList1.Any(p2 => p2.ID == p.ID));