Target actually offers a few options for their retirement saving program.
The 401k is the basic retirement system. These contributions are made pre-taxes, which lowers your income taxes. The trade-off is when you withdraw in the future, you'll have to pay taxes on whatever you withdraw. You can also withdraw money from this system as a loan. Again, this will be taxed when you withdraw any money from the system. It is not recommended to use your retirement savings account before you're actually retired.
Target also offers a Roth 401k program. The contributions are made after-taxes, which mean your earned income taxes now will be slightly higher. But, the trade-off is you won't have to pay any taxes again on any earning activity that happens. You do have to wait until you're 59+ to be able to withdraw tax-free. Hence, the retirement part of the savings program.
All funds (except for a select few, including Target stock) are Vanguard funds. Vanguard has created a few pre-sorted mixes based on expected retirement age called LifePath, that will offer consistent returns-on-investment (ROI). Vanguard is a fund management institute out of Philadelphia, PA. They don't manage the retirement program for Target, they just manage the stocks and funds that Target's financial advisor company, Alight Financial Advisors, selects from. The benefit of having Vanguard stocks is that Vanguard is a well-known financial institute with a strong track-record of ROI offerings.
If you're new to retirement saving or financial management at all; Alight offers an advisory service for better financial planning.
The company also offers $1 for $1 contribution matching, up to 5%.
targetpayandbenefits.com as
@Amanda Cantwell mentioned will get you into the benefit hub. The login is in the top-right corner. After you login, look or the Savings & Retirement tab and start poking around.