The Imperial Court (朝廷)
The Imperial Court was a place where an emperor performs political affairs and tasks. In other words, it was a government.
Chinese Imperial Court
Chinese Imperial Court was the ancient Chinese government which centered on an emperor and involved eunuchs such as Chancellor and the like.
The emperors of China, as well as of Japan, was succeeded by the male descendants of the founder (Gao Zong (高宗)) of the country. In China, a winner of domestic war - not necessarily a son of an emperor - asked an former emperor to transfer his power to him, and acceded to the imperial throne and chaged the name of the country. Thereafter the throne was succeeded as such.
The imperial title was called crown (帝位) in China and it was usually considered disloyal to take over it. However, a citizen could accede the imperial throne if he did not satisfy with the present emperor and hoped to do so. There were exceptions too, and in such cases, others defeated the emperor and conducted a reign of virtue.
The Imperial Court has not existed in China after the Qing Dynasty, and now the country is governed by the Chinese Communist Party. Puyi (溥儀), the last emperor of the Qing Dynasty, became the emperor of Manchukuo. The character of Manchukuo government was like the one of Japanese government after the Meiji period, and it is hardly called the Imperial Court.
Japanese Imperial Court
It was the place where an emperor conducted the affairs of state. It also refers to the government.
In Japan, from the ancient times (the Nara Period, the Heian Period) to the early Middle Ages (the Kamakura Period), the political system centered on an emperor was kept, and the Imperial court often means the government (gosho, or the Imperial Palace) in which an emperor carried out politics (however, the Imperial court was similar to Cloister government in wich Daijo Tenno, a retired Emperor, carried out politics).
The Imperial Court is called Chotei (朝廷) which literally means the morning court; the politics, conferences and the like were held before noon from early in the morning in the Nara period when Taiho Ritsuryo (Taiho Code) was set up and the political system of the Imperial Court was established,
In the period of military government, a bakufu (Japanese feudal government headed by a shogun) was sometimes called 'Chotei', too. Today, 'Chotei' is often used as the word comparable to a bakuhu; this is strongly influenced by the thoughts after the modern times in which the Emperor/aristocrat (the Government of kuge, or the court nobles) and buke (military government) oppose one another. As a matter of fact, the bakuhu also could not exist without the Imperial Court while keeping the characteristic of its own which is different from the one in the Imperial Court, such as Sekke Shogun and Miyashogun (shogun from the Imperial Court) from Kamakura bakufu, and Taisei-ininron (a theory holding that government powers were delegated to the Shogun by the Tenno) of Edo bakufu.
In the early Muromachi period, the Japanese government was separated into the Southern Dynasty of Daikakuji-to (imperial lineage starting with Emperor Kameyama) and the Northern Dynasty of Jimyoin-to (imperial lineage from Emperor Gofukakusa to Emperor Gokomatsu) which opposed one another. It is called the period of the Northern and Southern Courts (Japan).
The old Imperial Court system including the bakuhu was virtually abolished by the Meiji Restoration (the Decree for the Restoration of Imperial Rule), and the Meiji Government was established as a newly born political system. At this point, the Japanese Imperial Court as the premodern political system was ended and replaced by the government of Japanese Nation (or the Empire of Japan).