Employment taxes is where the organization must withhold certain taxes from employees paychecks. Employment taxes include Federal income tax withholding the Social Security and Medicare taxes. When it comes to social security, they pay for benefits that workers and families receive under the FICA. It also pays for benefits under old age, survivors and disability insurance part of the FICA. The social security tax is withheld from the employee's gross wages until the employee cumulative wages for the year reach the wage base limit. For self-employed and people employed by businesses, there is a difference because people who are self-employed are responsible for paying the same federal income taxes as everyone else. Self-employed people must keep track of their own income, estimate how much tax they owe, and in most cases, make estimated tax payments throughout the year.
References:
https://www.irs.gov/charities-non-profits/exempt-organizations-what-are-employment-taxes
https://turbotax.intuit.com/tax-tools/tax-tips/Self-Employment-Taxes/Self-Employed-Federal-Income-Taxes/INF14455.html