In animation, OP and ED are the theme songs at the beginning and end of the film. Usually sung by a singer, it provides background music or emotional atmosphere for the animation plot.
OP songs generally appear at the beginning of animation, bringing an opening atmosphere to the audience; ED's songs appear at the end of each episode, giving the audience a feeling of ending. These theme songs play an important role in animation, which can enhance the audience's emotional experience and better participate in the plot.