A great deal of hot air is talked about shrub roses making them complicated
as if studies in botany or garden design are needed before growing them.
This is enough to put off anyone who just wants to enjoy beautiful roses.
Here is a practical users'guide to shrub roses:

Most grow taller and wider than HTs and Floribundas.

Those with spreading or sideways growth are Landscape or Ground-Cover roses.

They can be put to all kinds of uses: the most important practical difference between modern shrub roses and HTs or Floribundas is the eventual size and shape of the plant.

Most modern varieties repeat bloom.

Many old varieties and species roses bloom once only in early summer.

Flowers of all shapes forms and sizes are to be found among shrub roses.

Some are perfumed some aren't. This applies to varieties both old and new.