The difference between the eldest son and the crown prince was their status and inheritance. The crown prince was the first heir of the emperor in feudal society. Only the legal heir (the eldest son of the emperor) could be called the crown prince or crown prince. The eldest son was the first son of the emperor. He might not inherit the throne, but it depended on the situation. Therefore, the crown prince was designated as the successor of the next generation and had the responsibility and status to inherit the throne, while the eldest son might not necessarily inherit the throne.

The difference between the eldest son and the crown prince was their status and inheritance. The crown prince was the first heir of the emperor in feudal society. Only the legal heir (the eldest son of the emperor) could be called the crown prince or crown prince. The eldest son was the first son of the emperor. He might not inherit the throne, but it depended on the situation. Therefore, the crown prince was the chosen heir to the throne and had a higher status, while the eldest son was only the son of the emperor and had a lower status.
The eldest son was not necessarily the crown prince. The crown prince was the first heir to the throne in feudal society, and was usually the eldest son of the emperor. However, the eldest sons of the Kangxi, Yongzheng, and Qianlong emperors were not the eldest sons of the Di, but the eldest sons of the Shu. Kangxi's eldest son, Yin, lost the position of crown prince because his mother was only a concubine and not his wife. Kangxi conferred the title of crown prince on his second son. Similarly, the eldest son of Yongzheng and Qianlong could not become the crown prince because of the difference in birth status. Therefore, although these eldest sons had stayed by the emperor's side for the longest time, they were not qualified to inherit the throne, nor were they called crown princes. Therefore, it could be concluded that the eldest son was not necessarily the crown prince.
In Joy of Life, the eldest princess and the crown prince did not have a son.
The crown prince was not necessarily the eldest son. In ancient times, the crown prince was usually the emperor's eldest son, the eldest son born by the empress. However, there were some exceptions. For example, in the three emperors of Kangxi, Yongzheng, and Qianlong, their eldest sons were not the eldest sons of the legitimate family, but the eldest sons of the concubines. Kang Xi's eldest son, Yin Bi, missed the opportunity to become the crown prince because his biological mother was only a concubine and not his wife. Therefore, it could be concluded that the crown prince was not necessarily the eldest son.
The difference between a legitimate eldest son and an illegitimate eldest son lay in their concept, status, and order of inheritance. The eldest son was the first son born to his wife, while the eldest son was the oldest son born to a concubine. In terms of status, the status of the eldest son was much higher than that of the eldest son. Regardless of whether he was the eldest son or not, as long as he was a legitimate son, his status would be higher than that of a concubine. In terms of the order of inheritance, the ancient system implemented the eldest son inheritance system. The legitimate son inherited the family's status and property before the illegitimate son. If there was no eldest son in the family, or if the eldest son died and had no descendants, then the eldest son could inherit. In short, there were obvious differences in status and inheritance rights between the eldest son and the eldest son.
The difference between a crown prince and a crown prince was their status and identity. The Crown Prince referred to the title of the heir to the throne, while the Crown Prince referred to the son of the current Emperor who was designated as the heir. The Crown Prince was the main body of the Crown Prince, usually the eldest son of the Empress. If the Crown Prince passed away, his younger brother or the oldest prince could inherit the position of Crown Prince. The crown prince was the crown prince who had already been confirmed as the heir. He would usually receive special education and training in preparation for the responsibility of the throne in the future. In short, the crown prince referred to the general title of the heir to the throne, while the crown prince referred to the heir to the current emperor.
There were a few reasons why the eldest son of Kangxi, Yin, was not made the crown prince. First of all, his mother was not the empress, but a concubine. In the tradition of choosing a crown prince, the son of the empress was usually the first. Secondly, the eldest son of Emperor Kangxi was not Yin Bi, but Cheng Hu, but he died young. According to his status, Yin He could not be made the crown prince. In addition, Yin's mother was Emperor Kangxi's wife, but she died shortly after Yin's birth. Emperor Kangxi missed her very much, so he made Yin Ni the crown prince shortly after he was born.
There were some differences in definition and status between the crown prince and the crown prince. The Crown Prince referred to the chosen heir to the throne, while the Prince was only the son of the Emperor. The Crown Prince's status was higher than the Princes, only second to the Emperor and Empress. The Crown Prince was the person who would rule the country in the future. If the Crown Prince became the Emperor, he and the Prince would be brothers, and there would be a difference between monarch and minister. Thus, the Crown Prince's status was even more honorable. In general, the crown prince referred to the successor to the throne, while the crown prince referred to the emperor's son.
The difference between a crown prince and a prince lay in their status and identity. The Crown Prince referred to the Emperor's eldest son, the heir to the throne, and had the qualifications to inherit the throne. The crown prince usually received strict education and training in preparation for becoming the future emperor. Princes referred to the other sons of the emperor. They did not have the qualifications to inherit the throne, but they still enjoyed special privileges and noble status. The princes also received education, but their main responsibility was to assist the crown prince and the emperor in participating in state affairs and ceremonies.
The difference between a Crown Prince and a Prince was their status and identity. The Crown Prince was the son of the Emperor, while the Princes were the sons of other royal families. As the son of the emperor, the crown prince had a higher status and privileges. He might have more official positions and responsibilities. However, the specific differences and details might require further research and information.