Illustration Portfolio for Uni

My general copy/paste portfolio advice is a combination of examples of iteration/development/design work (often the kind of thing you might do in A level), some drawings from life (e.g. still life, figure drawing, technical drawing) and imaginative work (work that demonstrates combining ideas imaginatively). Some places might request a variety of mediums, and this is often course-dependent. Always check the portfolio guidance that each university should supply, and this may be generic to the university or specific to that course.
Text is fine - you might want to format your pieces with accompanying text like on a Powerpoint/Google slides format, or have it accompanying if you're using a portfolio host website. It's often useful for explaining your ideas, crediting any external resources you used, stating what medium you used.
Student room has a great resource too. You can find that here

Any tips for a portfolio? I've applied to BA (Hons) Illustration at two uni's and would really appreciate any ideas what I can include on a portfolio.
If it ok to add text explaining pieces? Or is it preferred to just have the art?