Both byte and char are numeric data types in Java. They are used to
represent numbers in a specific range.
Major difference between them is that a byte can store raw binary
data where as a char stores characters or text data.
Usage of char is E.g. char ch = ‘x’;
Byte values range from -128 to 127.
A byte is made of 8 bits. But a char is made of 16 bits. So it is
equivalent to 2 bytes.
https://www.geeksforgeeks.org/difference-between-byte-short-int-and-long-datatype-in-java/