Land Travel:
US and Canada: Both have Nexus Lanes and Booths

Air Travel:
Canada: Nexus Machines are installed at designated Canadian Airports only. No Global Entry Kiosks.
USA: Global Entry Machines are installed at designated American Airports only. No Nexus Kiosks.

So for Air Travel Analogy: Canada is to Nexus as USA is to Global Entry.



More Specific Cases for American and Canadian Citizens:

Going from Canada to the USA or vice versa by Land Crossing:

Use Nexus Lanes on either side of the border.


Going from Canada to the USA by Air:

Use Nexus Kiosk in Canadian Airports with US pre-clearance locations (for example, YYZ)
When you arrive in the USA, you have been pre-cleared, no need to be inspected, walk out.

Going from USA to Canada by Air:

Board the plane from LAX as usual. When you land at a Canadian Airport, use Nexus Kiosk (to clear with Canadian Customs) if there is any. Walk out if cleared.

So When Do You Ever Use Global Entry Kiosk as a member of both Nexus and Global Entry?

When you enter the USA from a Canadian Airport with NO US pre-clearance section.

When you enter the USA from any other country aside from Canada.



Let us use the following as an example: YYZ, LAX and MNL (another country)

From Canada --> USA --> Another Country

From YYZ - LAX (Use Nexus in YYZ to clear US Customs).

From LAX - MNL (Regular Procedure for all Travellers)



From Another Country --> USA --> Canada:

From MNL - LAX (Use Global Entry in LAX to clear US customs)

From LAX - YYZ (Use Nexus in YYZ to clear Canadian customs)