Do you imagine that the computers of the 1960's were built to handle audio data?
No—certainly this was not a common use for computers then.
But some 1960's computers did deal with audio data; it was merely a case of inventing a way to represent audio with bit patterns and then writing the programs for it.
It would be awkward if every time you used data you had to invent your own scheme to represent it with bits. There are types of data that are so fundamental that ways to represent them are built into Java. These are the primitive data types. The eight primitive data types are:
Upper and lower case characters are important. So "byte" is the name of a primitive data type, but "BYTE" is not. Computer languages where case is important are called case sensitive. Some languages are not case sensitive, especially old languages that were designed when data entry equipment did not have lower case characters.
In the phrase primitive data type the word primitive means "a fundamental component that is used to create other, larger parts." This word is used frequently in computer science. To solve a large problem, you look for the primitive operations that are needed, then use them to build the solution.
Int a primitive data type?