Why is Britain considered a democracy and not China when Britain has a royal family while China is a republic?

Because of Fu Manchu.

Because Britons have a choice of the people they can elect to govern them.

UK has a constitutional monarchy. The Queen is head of state but does not run the country. That is done by a democratically elected government.

There are no open elections in China. A large proportion of republics are not democratic. Many are similar to old fashioned absolute monarchies.

LOL, China a republic.

Good one

The UK elects its leaders. In China the communist party appoints them. The royal family does ceremonial stuff, and not much more.

China a republic? Why, because the official name is "People's Republic of China?" North Korea is officially the "Democratic People's Republic of Korea." And if you think either of these are Republics or Democratic, then you might also buy bags of sh*t from Amazon.

Britain isn't communist, China is.

Almost all (if not all) nation states have a Head of State - whether they're republics, actual monarchies or nominal monarchies. The United Kingdom of Great Britain and Northern Ireland is a nominal monarchy where it is universally acknowledged that Her Majesty Queen Elizabeth II is our Head of State but is without any degree of governmental power whatsoever. Our government is bicameral and our principal House is democratically elected. Consider some examples of republics where the Head of State is more or less omnipotent such as USA, France, Italy or Russian Federation. Turkey is an example of a republic where the Head of State has proclaimed himself to be the leader for life and therefore is essentially unelected and directly in control of all of the state's key functions.

the royal family have no constitutional power

The Royal family are just figure heads, they haven't had any real power since I don't remember. The people in charge are elected in a two-party system. China is a dictatorship now that what's-his-face crowned himself king last year............