inform (someone) about (something)
To share information about something with someone. Have you informed Phil about the time change for Saturday's dinner? Don't worry, I'll inform the investors about your illness, and we'll reschedule the meeting.
inform someone about someone or something
to tell someone about someone or something. How is my friend Tom getting on? I asked you to inform me about him from time to time. Please inform me about the state of the contract for the book.