Personal Brand
The combination of reputation, positioning, and public presence that shapes how other people perceive you professionally.
A personal brand is how you are known professionally: the impression people form from your website, LinkedIn, content, speaking, and reputation, whether or not you have deliberately shaped it. Everyone with any public or professional presence already has one; personal branding is the practice of making it clear and intentional instead of accidental.
Example
A consultant's personal brand might be built around being the clear, no-nonsense expert in a specific niche, reflected consistently across their website, LinkedIn, and speaking topics.
Nuance
A personal brand is not the same as a logo or a website. Those are assets that express the brand; the brand itself is the perception in other people's minds.