In ancient times we were subjects of kings in our country. today we are citizens of our country. what is the difference?

In some countries still ruled by a king or queen it's not much different. But in a place like America where the government is a sort of Democratic Republic we have a President rather than a king. The President has the final word on most issues but our country is truly run by a Senate and House of Representatives. This prevents complete control by one person and introduces the Checks and Balances system where the are certain balances on the power of each body of our government. Even countries still ruled based on monarchy (king/queen) have adopted certain Checks and Balances. Too much power for one person (as we have learned throughout history * cough cough * Hitler * cough cough*) is never a good thing. But this is a very loaded question as there are so many different forms of government throughout the world and this doesn't even take something as important as religion or culture into account. Basically, in the past kings were generally given ALL the power and today we try to balance the power of a leader between them and some type of representation of the "people." Hope this all make sense and answers your question!