Pseudo-column rownum____oracle in Oracle

Pseudo-column rownum in Oracle
Pseudo-column rownum, just like columns in a table, but not stored in a table. Pseudo-Columns can only be queried and cannot be added to the deletion operation. It generates a serialized number for each piece of data based on the result returned. RowNum is a pseudo column of Oracle

What the rownum can do:

rownum can only equal 1 if you make it equal to the other number, you can't find the data .
For example:
Select Last_Name
From S_emp
where Rownum=1;

rownum greater than 0 if you make it larger than the other number, you cannot find the data
For example:
Select Last_Name
From S_emp
where rownum>0

rownum can be less than any number
For example:
Select Last_Name
From S_emp
where rownum<7