If you send your resume by email, it is best to have a simple subject or title, such as: xxx applies for xxx's position, etc. , it is convenient for HR to check the resume and give a good impression.

This is generally unnecessary. If it is aimed at a certain position (such as administrative assistant), an industry (such as e-commerce), or yourself (such as this year), it can also be combined appropriately (such as the resume of fresh graduates of e-commerce).