The function of the label pseudo-directive

Labels are generally used as properties that define variables and labels, and are related to the next variable and label definition statement, which can be of type Byte, WORD, DWORD, QWORD, near, far, and so on.
to use:
buffer (variable) label     BYTE (type)

For example:
Buffer1        label       WORD
Buffer2        DB          20  DUP (?)
Typically, the next statement immediately defines a different type than the one specified by label. In fact, Buffer1 is the alias of Buffer2, which points to the same storage address in memory.
in other words, the same set of data defines two different types, and you can specify the corresponding labels when you accept access to different data types. When
accepting a Word type data access, use Buffer1; Buffer2 is used when accepting byte-type data access. Otherwise, the compiler will compile with an exception because the data type does not match.