what is this Skilled Occupations (NOC A, B, 0) ?????????????Confused

[soy]

Hello
If i am getting study permit visa as a full time student .After six month i will apply for work permission
then may be i will get job as ( Cashier ,Receptionest ,Data entry clerk , etc )
when i finish my graduation and 2 years of my work experience i want to apply for PR ( permenent residance )

is this ( Cashier ,Receptionest ,Data entry clerk , etc ) job is under (NOC A, B, 0) to help me For PR