Answers;
(1). Yes agreements are under the law---eg.Labour contract agreement under the contract atc. duration preferably 11 months.
(2) all workers under the contract are casual or contract workers and bound to obey comp.'s rules and regulations and also rights to enjoy some of the recreation activities under the org.and They should not complete 240 days in a year and required to give break....While temporary employee is like Trainee for the duration of 6months, or 1 year.
(3)Trainee and those who are directly employed by org. on contract basis, required to complete decided Notice period mentioned in the organisation's letter which was issued to him/her at the time of employment. And if leave before Notice period, org. is liable to deduct salary for the left days of Notice..
(4) Gratuity is payable only after completion of 5years. under the Gratuity Act. Above all.... contract laborers fall under the Contract Act and rules and bonds to be followed by them mentioned into the Agreements between comp. and contractor otherwise. rules and regulations of the company in case if you get confused.