The pound is a unit of mass, same as the kg (it's defined as exactly 0.45359237kg). Just as 900kg is 900kg everywhere, 2000lb is 2000lb everywhere. The colloquial weight is literally a force, and its imperial unit is thus the pound-force.
This is incorrect. The pound is a unit of force, similar to a Newton. The pound-mass(notated lb-m) is similar to the kg. The conversation you gave above is based on Earth gravity for weight.
There are about a dozen different units that are all called "pounds," and you have to rely on context to know which is meant. When I took physics in high school, pounds were always force (abbreviated lbf) and we used slugs for mass ( https://en.m.wikipedia.org/wiki/Slug_(mass) )
