Similarities: Both are based on the idea that young humans need protection and have the best interest of the child in mind and both also understand that children need not only basic human needs, but also need to be loved by older individuals.
Differences: There are a few gender differences in both documents for instance, UNDRC often uses the patriarchy way of describing gender norms for example they called all children "he" and put an emphasize of mothers raising children whereas the UNCRC uses "he or she". Furthermore, the UNCRC is generally a more all-inclusive list of rights, listing all rights one could imagine except LGBTQ rights wheres the UNDRC is far less inclusive.