Employers who provide retirement plans retain and attract employees who are seeking careers instead of temporary jobs. Studies suggest that the existence and quality of retirement plans are one of the top reasons employees stay long-term with an employer.*
401k/403b - This is an employer based retirement plan. They have higher amounts you can invest per year and typically have some kind of employer match contributions. Most of these accounts have both a Traditional and ROTH option inside of them. Employers can setup requirements to entry and vesting this such as 90 days of employment or 1 year on the job before participation (also known as a vesting schedule). Many employers setup growing match based on years of service to that employer.
457 Plans - Virtually the same as a traditional employer sponsored plan but is typically available only for government employees and schools. These accounts do not have an early withdrawal penalty prior to the age of 59 ½ like most retirement plans.
SEP IRA - Individual Retirement plan designed for a self employed individual with minimal employees.
SIMPLE IRA - This is a low cost group retirement plans for employers & employees, but requires a 3% minimum contribution from the employer with less flexibility than a 401k or 403b.
*Multi-country survey finds most workers cite pension and retirement benefits as critical factor when deciding to accept or stay in a Job. Business Wire. (2019, July 11). https://www.businesswire.com/news/home/20190711005002/en/Multi-Country-Survey-Finds-Workers-Cite-Pension-Retirement