Substitution ciphers

Substitution ciphers are like the cereal box decoder rings (R=A, F=B, Z=C, etc.) Each different “ring” is called an alphabet
They can be jazzed up with multiple alphabets (first letter uses alphabet #1, second uses #2, etc.) a.k.a polyalphabetic ciphers
Substitution of groups of characters is referred to as polygram substitution (ALA=FQD, etc.)

Substitution ciphers are like the cereal box decoder rings (R=A, F=B, Z=C, etc.) Each different “ring” is called an alphabet