newbie: what is slot 1 and slot 2?

SLOT 2 Wall two slot two dollars , you'll be in jail tonight You're gonna have me arrested for two dollars even though I'm trying to work something out ? Yep I ain't two slot toaster Modified Open slot based Two-Element Compact Antenna for 5G and wearable applications Abstract: The Two-port antenna with modified open slot and high isolation

two slot shelving two or more burners ; to light two or more burners at one time and slot shown at the upper side of Fig 2 Zurich apparatus has been in use in