the definition of the rowid in oracle database

Question

I am confused about the definition about rowid when I doing the following question. which one is correct?

A ROWID is: 1.An integer in the form of a sequence number associated with each row as it is retrieved from the database.
2.A base-64 number indicating the physical location of a row within the database data file.

Answer 1

You are confusing rownum with rowid.

the ROWID pseudocolumn returns the address of the row. Oracle Database rowid values contain information necessary to locate a row.

https://docs.oracle.com/cd/B19306_01/server.102/b14200/pseudocolumns008.htm

the ROWNUM pseudocolumn returns a number indicating the order in which Oracle selects the row from a table or set of joined rows

https://docs.oracle.com/cd/B19306_01/server.102/b14200/pseudocolumns009.htm

select rowid, rownum, name from sys.system_privilege_map
where rownum < 10;

ROWID   ROWNUM  NAME
AAAAFtAABAAAAiBADP  1   FLASHBACK ARCHIVE ADMINISTER
AAAAFtAABAAAAiBADO  2   ALTER DATABASE LINK
AAAAFtAABAAAAiBADN  3   ALTER PUBLIC DATABASE LINK
AAAAFtAABAAAAiBADM  4   ADMINISTER SQL MANAGEMENT OBJECT
AAAAFtAABAAAAiBADL  5   UPDATE ANY CUBE DIMENSION
AAAAFtAABAAAAiBADK  6   UPDATE ANY CUBE BUILD PROCESS
AAAAFtAABAAAAiBADJ  7   DROP ANY CUBE BUILD PROCESS
AAAAFtAABAAAAiBADI  8   CREATE ANY CUBE BUILD PROCESS
AAAAFtAABAAAAiBADH  9   CREATE CUBE BUILD PROCESS

ROWID is very rarely used in queries. ROWNUM on the other hand is used very frequently to restrict number of results, as shown above.