Max is an option you can purchase which has a variety of benefits. It is NOT a TurboTax edition like the Deluxe edition to assist in completing a tax return.
See this TurboTax support FAQ for Max - https://ttlc.intuit.com/community/choosing-a-product/help/what-is-max/01/26700
MAX is an add-on option that is in addition to the TurboTax edition selected. It is a suite of extra benefits that costs an extra $45 or so, in addition to the TurboTax product fee. Read what is included below:
FAQ: What is MAX?