Broadcaster Katie Couric looks at our changing understanding of what gender means in a new documentary set to air on the National Geographic channel.

The two hour long documentary follows the January edition of the respected magazine which provided a focus on gender issues.

The trailer for the series shows Couric finding out about what its like to raise a transgender child, finding out about appropriate pronouns, and the legal issues that need to be addressed.

The journalist meets people who are intersex and transgender and their families and shares their stories and challenges.

The Gender Revolution airs on National Geographic People on Foxtel at 5:30pm on Wednesday.