Glossary

AI headshot terms, defined.

Quick definitions for the technical terms behind AI headshot generation.

• AI Headshot Glossary

  Plain-English definitions for AI headshot terms: Gemini 2.5 Flash Image, diffusion models, identity preservation, upscaling, face embeddings, and more.

• AI Headshot

  An AI headshot is a generated portrait conditioned on your own face. How that differs from a filter, from a real photo, and from a deepfake, in plain terms.

• InstantID

  InstantID is the method that lets a model keep your face recognizable from a single reference photo, with no per-person training. How it works and where it breaks.

• Face Embedding

  A face embedding is the short list of numbers a model uses to mean you. How it is measured, why it decides whether a headshot still looks like you, and its limits.

• Real-ESRGAN

  Real-ESRGAN is the open-source upscaler that adds resolution without turning skin plastic. What it does, where it fails, and why headshot tools run it last.

• Stable Diffusion

  Stable Diffusion is the open model family most AI image tools are built on. How diffusion turns noise into a photo, which versions matter, and what it costs.

• Diffusion Model

  A diffusion model starts from pure noise and removes a little of it at a time until a photo is left. What that means, why it works, and what it costs to run.

• LoRA

  LoRA teaches a big image model one small thing, like your face, without retraining all of it. How the adapters work and why headshot tools lean on them.

• Identity Preservation

  Identity preservation is the hard part of AI portraits: keeping the result recognizably you, not a good-looking stranger. How it is measured and why it fails.

• Image Upscaling

  Upscaling adds pixels an image never had. The difference between plain interpolation and a learned upscaler, and why the second one can invent detail that lies.

• Professional Headshot

  What separates a professional headshot from a good photo of you: lighting, framing, background, wardrobe and eye line. The definition, plus the working checklist.

• Nano Banana

  Nano Banana is the codename for Google's Gemini 2.5 Flash Image model. Where the name came from, why it went viral, and what it can actually do with faces.

• Gemini 2.5 Flash Image

  Google's identity-preserving image model explained: how it replaced per-user training, its strengths and limits, and how tools build on it.