What is the difference of 而且 and 并且？

而且 (ér qiě):
It is more commonly used in both written and spoken language.
It is often used to connect statements that are related or sequential, emphasizing additional information or factors.
It can be used to express a logical relationship between the connected clauses.

Example:
他很聪明，而且很努力。
(Tā hěn cōngmíng, érqiě hěn nǔlì.)
He is very smart, and moreover, he works very hard.




并且 (bìngqiě):
It is also used to connect statements, but it tends to emphasize a stronger logical relationship between the clauses.
It can convey a sense of "not only this, but also that" or "moreover" in a more explicit manner.

Example:
我们需要保护环境，并且节约能源。
(Wǒmen xūyào bǎohù huánjìng, bìngqiě jiéyuē néngyuán.)
We need to protect the environment, and moreover, conserve energy.