Most full-time, part-time or casual employees in NSW are entitled to long service leave. If you've been with the same employer for 10 years, you're entitled to 2 months (8.67 weeks) paid leave, to be paid at your ordinary gross weekly wage.
By law, there's also a pro-rata entitlement after 5 years if you resign as a result of illness, incapacity, or domestic or other pressing necessity. If you cease employment before 5 years service, there's no entitlement for long service leave.
To work out how much long service leave you've accrued, use this online long service leave calculator.