Perennials are long-lived plants that are there every year. Herbaceous means that the foliage dies off in autumn but grows again the following spring.

So, just to add my bit, Perennials can be evergreen, whereas herbaceous ones are deciduous.

Thank you both for your replies very very helpful

What a sensible good question you asked.

Eminently sensible question, Ladygardener!
Techically, a perennial is any plant that lives more than 2 years, including trees and shrubs. Herbaceous perennials are those that have little or no permanent woody structure, such as mums or daylilies. However, most gardeners use the word "perennial" to refer only to herbaceous perennials, since in practical usage, well, trees and shrubs already have their own names, right?

thank you so much all been so helpful