Both the Shark IQ and Shark AI robot vacuum series have a few models, you can read the comparison of some of the Shark IQ robots, and AI robots comparison to learn more on each series.

The main difference between the Shark IQ and AI robot is:

images from Shark official site infomercials

• AI Laser Vision
  The Shark AI robot is a newer series, it features Shark’s most advanced vision module – AI Laser Vision which makes Shark’s IQ Navigation smarter, it helps the robot detect and avoid objects. The better thing is that it supports virtual no-go zones. It can respond to the no-go zones you set up in the app. Meanwhile, the AI robots can still recognize the physical BotBoundary strip.
  To keep the IQ robots from certain spots, you need to use the physical boundary strip, they does not support virtual boundary.
  The AI Laser Vision also enables the AI robot to run properly in low light conditions because the AI Laser Vision is not dependent on ambient lighting.
  Whereas the IQ robots will not navigate correctly in the dark, it cleans but it will not move in a row by row pattern. Because it needs light to know where it’s going. For better cleaning performance and coverage, it is recommended to turn on the lights when running the IQ robots at night or in low light conditions.
  P. S.
  The AI robot will only avoid objects taller than 2.8 inches. Anything lower than this height will not be recognized.
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• Sonic Mopping
  The AI robot includes a vacmop version, including Vacmop RV2000WD and Vacmop Pro RV2001WD, which features sonic mopping that scrubs 100 times per minute. With the mopping module, the robot can vacuum and mop hard floors at the same time. The mopping kit includes a fluid reservoir and a mopping pad. The Vacmop packages also come with a trial size bottle of solution.
  Whereas all the IQ robots are not compatible with the mopping kits.
• Self Empty
  Though the AI robot is the newer series, it does not support the Self Empty Base which the IQ Self Empty series features. The IQ Self Empty robots come with a self empty base that holds dirt and debris up to 30 days of cleaning. The robot equipped with an Empty & Resume feature that allows the robot to return to its base after 30 minutes of cleaning to empty its dust bin, then resume its cleaning session. This feature can be disabled in the app. Shark recommends to turn this on for high traffic areas and homes with pets.
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• There are also some less important difference, such as the dust cup capacity, dimensions, and weight.

Similarities:

• Self-cleaning brushroll to remove pet and human hair, long and short hair as the robot cleans your home, without hair wrap on the brushroll.
• Two spinning side brushes to pull in debris from edges and corners.
• The robot can create a map of your home, and allows you to choose to do whole home cleaning or which rooms to clean.
  The robot methodically cleans your home row by row, not in a random pattern.
• You can control the robot via the SharkClean app.
• Voice control is compatible with Amazon Alexa and Google Assistant.
• When the cleaning cycle is complete, or if it is low in battery, the robot will search for the charging base, return to the dock to recharge itself, and resume cleaning where it left off.
• Have cliff sensors to detect stairs and ledges to avoid falling down.
• Come with charging dock for the robot to dock and recharge itself.
• Powered by 14.4V lithium-ion battery.
• Expected charging time is 6 hours.
• Carry one year limited warranty.