Unsure what this Eigenvalue means?

In this Eigenvalue/vector question, the Eigenvalue v in the question is (-1,1,1)ᵀ. I’m not sure what to make of this, I don’t understand if it’s a list or something, or what the superscript T is. I haven’t linked the full question, I just need to understand this first bit. Any help is appreciated.

photo of the eigenvalue