Employer and Employee relationship.
1.If an employee receives salary from an employer, then the income is taxable under the head Income from Salaries .
Thus, there should be proper employer and employee relationship between payer and payee for income to be taxed under Income from Salaries.
Employee on payroll in a Company
2.I f there is no such relation then income is taxable under Income from other sources or Profit and gains of business and profession(PGBP)
Example:-Person working on contract in a Company are taxed under PGBP