The differences between Shark Cordless Pro stick vacuum cleaners IZ562H and IZ540H are as follows:

Odor Neutralizer Technology
The most obvious difference between them is the odor guard kit.
The IZ562H has an odor neutralizer dial on the nozzle that you can adjust to guard against bad odors from debris you pick up for a fresh-smelling home, whereas the IZ540H does not have this kit.

Attachments
The IZ562H comes with (1) Duster Crevice Tool and (1) Pet Multi-Tool whereas the IZ540H comes with (1) 8-inch Crevice Tool.

Color
The IZ562H has blue color on the hand unit whereas the IZ562H has mint color.

Check IZ562H Price at Amazon

Similarities between these cordless Shark vacuums:

• Design
  They are stick and handheld 2-in-1 vacuum cleaner.
• Wand
  They use a straight wand, not flexible wand.
• Dust Cup
  They have a have bin capacity of 0.18 gallons.
• Brushroll Design
  They have a brushroll that combines soft microfibers and flexible silicone fins into one for picking up large debris and fine dust.
  Self cleaning brushroll reduces hair wrap issues.
• No Brush On/Off Control
  Brushroll spins in all modes.
• Modes
  They have Eco,Clean Sense IQ and Boost mode.
  The Clean Sense IQ uses infrared sensor to sense the dirt you can’t see and automatically adjust the suction power for optimal cleaning performance and runtime.
• LED display
  They have LED display with real-time readouts to monitor battery, select suction levels, and engage Clean Sense IQ.
• Removable Battery
  Removable battery allows you to charge in or out of the vacuum, you can also buy an extra battery to extend run time.
• Max Run Time
  The max run time is 40 minutes in ECO mode.
• Charge Time
  Full charge takes approximately 3.5 hours.
• LED Headlights
  To illuminate low light areas and help find hidden debris.
• Anti Allergen Complete Seal System with HEPA filter
  Captures and traps dust, allergens, dander, and particles down to 0.3 microns, keeping them out of the air you breathe.

For more comparison info, you can read the table below: