help with Database startup and shutdown: I did not get what the mean here

1)QueryandSetInitializationParameters:

a) Connect as user SYS with the SYSDBA privilege using SQL Plus.

b) Display the basic parameters using the below query:

 Select name, value, isdefault from v$parameter Where isbasic=TRUE order by name; 

(6) Show the value for PROCESSES and SESSIONS parameters.

c) Execute one statement in which you change the value for PROCESSES parameter to 240 in SPFile.

(7) Show the statement from Step c).

d) Execute a startup force.

(8) Show the value for PROCESSES and SESSIONS parameters after the restart.

e) Change the value for NLS_LANGUAGE parameter for your session only to Spanish.

f) Confirm that the change has worked by running:

 Select to_char(sysdate, 'day month') from dual; 

g) Change the value for NLS_LANGUAGE parameter back to English.

h) Execute the following statements regarding the OPTIMIZER_MODE parameter:

alter system set optimizer_mode=all_rows scope=both;

alter system set optimizer_mode=rule scope=memory;

Select value from v$parameter where name='optimizer_mode'

Union

Select value from v$spparameter where name='optimizer_mode'; alter system set optimizer_mode=all_rows scope=both;