They both have official royal titles, as third and fourth in line to the throne.
But while Prince George's future children would also have HRH status, any children that Princess Charlotte has are unlikely to be princes or princesses.
According to the Daily Mail, an expert has revealed Charlotte's future offspring would not be automatically be given royal titles - because these are inherited through sons, not daughters.
This is the case with Princess Anne's children Zara Tindall and Peter Phillips, who do not have HRH status, while Prince Andrew's daughters, Princesses Beatrice and Eugenie, do.
Speaking to Town & Country, Lucy Hume, associate director of etiquette experts Debrett's, explained: "Royal titles are inherited through sons, so if Princess Charlotte has children they would not automatically inherit the titles HRH, Prince, or Princess."