safe and secure 

safe: “safe” is the opposite of “dangerous.” We use “safe” to describe things that do not cause physical harm. Example:
I think the mining dams are not safe!

secure: We use “secure” to talk

  •  about something not at risk to be damaged, lost, or intercepted. Example: My passport is secure in a fire-proof box in my room.
  • about someone confident. Example: He’s very secure about  this situation. (used here to mean “confident”)