In case you mean the Online web version vs the Desktop CD/Download program
The Online web version is only good for one account and one return. You can log in and access your return from any computer. You only can see the forms after you pay and download the pdf. And you might need to upgrade to a higher version to enter different kinds of income. There are 4 Online versions. And you can add LIVE service or Full Service for expert help. In Online the fees are to prepare the federal and state returns (State is a separate charge) whether you efile or print and mail. Efiling is free and included.
You can see the prices and start an Online return here,
https://turbotax.intuit.com/personal-taxes/online/
The CD/Download Desktop you buy and install the program, which can do unlimited returns. The returns are only saved on your computer and can not be accessed from anywhere else. And not saved at Turbo Tax. So Be sure to save Frequently and make backups. You get 5 federal efile for free. In Deluxe and above you get 1 state PROGRAM download to prepare unlimited state returns (in that state). Each state return including the first one is $20 early or $25 to efile or you can print and mail the state for free. The Desktop programs do not have the expert help that is available to add to Online versions.
Desktop also has many other features and advantages over the Online version. You can do more than 1 return. You can see and enter into the actual forms. It has a What-If worksheet. And you can use a lower version because all the Desktop versions have ALL the same forms. You just get more help in the higher versions. In online you have to upgrade to enter certain kinds of income. Like Premier for investments.
And the Desktop program is always available even after the year ends. Which is good if you ever need to amend your return after online website is closed or get audited and need your tax records.
You can buy the Desktop CD/Download program here,
https://turbotax.intuit.com/personal-taxes/cd-download/
