partioning question

[asmaa atef]

Hello every one,
i want to ask about partioning
suppose this create statement
CREATE TABLE members (
firstname VARCHAR(25) NOT NULL,
lastname VARCHAR(25) NOT NULL,
username VARCHAR(16) NOT NULL,
email VARCHAR(35),
joined DATE NOT NULL
)
PARTITION BY RANGE( YEAR(joined) ) (
PARTITION p0 VALUES LESS THAN (1960),
PARTITION p1 VALUES LESS THAN (1970),
PARTITION p2 VALUES LESS THAN (1980),
PARTITION p3 VALUES LESS THAN (1990),
PARTITION p4 VALUES LESS THAN MAXVALUE
);

i want to know what is meant by partition p0 ,p1,...
and if is they repesent a physical storage or what?
and what is the step that precede creating the table to make partioning
i need an answer for this necessary and thanks in advance.
asmaa