Apresident has the power to cancel some parts of a new law. what makes this possible?

Take a moment to consider other countries and their form of government. select a country that does not utilize the same form of democracy that the united states uses, identify the country you chose and compare their form of government to the u.s. how are the different types of government the same? how do they differ? which type of government do you think is more beneficial to it's citizen's?