A page from the #uxn tutorial notes titled "The Instruction Cycle". It explains the line |0100 LIT 68 LIT 18 DEO and shows uxn riding a bike saying: Once I read a byte I decode it as an instruction and perform it.
https://assets.merveilles.town/media_attachments/files/107/797/364/083/990/673/original/871abb99f0c26286.png