Oracle Database Discussions

hai to all

i am a new bie

when i am reading a book i am a bit confused about the below para.

a pfile can optionally contain a definition to indicae use of an spfile. this is only way to start the instance with an spfile in a non default locaiton. to start the database with an spfile non in the default location,
spfile =<full path and file name> must be placed in the pfile.

any body can explain what sense it makes

ur cooperation will be highly appreciated