Query about mysql replication

after replication, we see status by following command :

show slave status\G;

in it’s output, we have to check following results:

Slave_io_running=yes

Slave_sql_running=yes

But, if we see

Slave_io_running=No

Slave_sql_running=No
in results
tht means replication is not done correctly ? is it like tht ?

as far as my knowledge, these IO & SQL threads wil run , when we execute any query on Master server .

so if i m not executing any query on Master server…. & getting “NO” in result (of query : show slave status\G;) on slave server..

then it doesn’t mean that there is something wrong in replication steps…

Please Advice !!