What is your mantra example?

Could you please elucidate with an example, what exactly constitutes a mantra? I'm quite interested in understanding how it differs from a regular phrase or saying, and how it can be effectively utilized in daily life. Could you provide a specific instance of a mantra, maybe one that has personally resonated with you or holds significant meaning? I'm keen to grasp its essence and how it can serve as a guiding principle in moments of need or inspiration.