春蚕到死丝方尽蜡炬成灰泪始干，是中国古代的一句典故。它描述了春蚕在吐丝的过程中，不断地将自己的生命凝聚在丝线之中，直到丝线终于吐完，它们也就彻底死去了。这句话的意思是指一个人在追求某个目标时，必须不断地投入精力和时间，直到目标被实现。这是一种不畏艰难困苦的精神，也是成功的必要条件。

The Chinese idiom '春蚕到死丝方尽蜡炬成灰泪始干' describes the process of spring silkworms spinning their silk until they die. It means that in order to achieve a goal, one must constantly invest time and effort until the goal is achieved. This is a spirit of perseverance and determination, which is also a necessary condition for success.