I'm not sure what the precise definition would be. But I was mostly thinking of web-based solutions. Like the difference between a custom solution that could potentially require an entire team of developers vs a shop that, for example, specializes in customizing WordPress templates. Even though there is some customization involved, it's an example of what I would define as "cookie cutter" solution in web development.

And I think that same concept probably translates over to the difference between consulting firms building fully custom solutions vs. consulting firms coming in to customize licensed software (like Microsoft or Oracle, etc).