100% Hydration Starter.

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 I was reading a recipe for a baguette using sourdough and it talked about hundred percent hydration starter.  Is this regular starter or is this something different ?

It is just a starter containing equal weights of flour and water. If that's your regular starter, then it is a regular starter. If your regular starter is 75% or 125% then you'll need to build a starter with this hydrations specifically if you want to follow the recipe exactly.