De jure (in Classical Latin de iure) is an expression that means "concerning law", as contrasted with de facto, which means "concerning fact" or "according to law".

De jure = 'Legally', De facto = 'In fact'.

The terms de jure and de facto are used instead of "in law" and "in practice", respectively, when one is describing political or legal situations.

In a legal context, de jure is also translated as "concerning law". A practice may exist de facto, where for example the people obey a contract as though there were a law enforcing it, yet there is no such law. A process known as "desuetude" may allow de facto practices to replace obsolete de jure laws. On the other hand, practices may exist de jure and not be obeyed or observed by the people.

It is, in fact, possible to have multiple simultaneous de jure legalities that are not de facto. Between 1805 and 1914, the ruling dynasty of Egypt ruled de jure viceroys of the Ottoman Empire, but acted de facto independent rulers who maintained a polite fiction of Ottoman suzerainty. However, from about 1882, the rulers had only de jure rule over Egypt, as it had by then become a British puppet state. Thus, Egypt was by Ottoman law de jure a province of that empire, but de facto was part of the British Empire.

Rosa Louise McCauley Parks (February 4, 1913 – October 24, 2005) was an African-American civil rights activist, whom the U.S. Congress called "the first lady of civil rights", and "the mother of the freedom movement".

On December 1, 1955, in Montgomery, Alabama, Parks refused to obey bus driver James F. Blake's order that she give up her seat to make room for a white passenger. Parks' action was not the first of its kind to impact the civil rights issue. Others had taken similar steps, including Lizzie Jennings in 1854, Homer Plessy in 1892, Irene Morgan in 1946, Sarah Louise Keys in 1955, and Claudette Colvin on the same bus system nine months before Parks, but Parks' civil disobedience had the effect of sparking the Montgomery Bus Boycott.

Parks' act of defiance became an important symbol of the modern Civil Rights Movement and Parks became an international icon of resistance to racial segregation. She organized and collaborated with civil rights leaders, including boycott leader Martin Luther King, Jr., helping to launch him to national prominence in the civil rights movement.