the CD version is for installation on a full PC or MAC. it has both step-by-step mode/interview mode (same as online) and also forms mode where you can go to the form to enter the data. you can e-file up to 5 returns for free. some versions include one free state but there's a fee to e-file it. you can use it to do what-if scenarios for free (non-filing)
system requirements
https://turbotax.intuit.com/personal-taxes/cd-download/tta-system-requirements
download site
https://turbotax.intuit.com/personal-taxes/cd-download
more help the higher the version (not live help)
To file a return for a prior tax year
If you need to prepare a return for 2018, 2019 or 2020 you can purchase and download desktop software to do it, then print, sign, and mail the return(s)
https://turbotax.intuit.com/personal-taxes/past-years-products/
You may also want to explore purchasing the software from various retailers such as Amazon, Costco, Best Buy, Walmart, Sam’s, etc.