Are Google symbols free to use?

Could you elaborate on the matter of Google symbols and their usage? Specifically, I'm wondering if these symbols, which are often associated with Google's various products and services, are freely accessible for use by the general public? Is there a license or permission required to incorporate them into one's own projects, whether it's for commercial or non-commercial purposes? Additionally, are there any restrictions or guidelines that must be adhered to in order to avoid infringing on Google's intellectual property rights? Clarifying these points would help me understand the legalities and best practices surrounding the utilization of Google symbols.