Final answer:
Republic Act No. 7877 is the law that bans sexual harassment in the workplace and educational institutions, ensuring safe environments for work and learning.
Step-by-step explanation:
The landmark law that bans sexual harassment in the workplace and in educational institutions is Republic Act No. 7877. This law is crucial for ensuring a safe working and learning environment, free from unwelcome sexual advances or conduct that can interfere with an individual's performance or create a hostile environment. Schools and other institutions have established codes to protect students and staff and uphold this law's standards.