All mothers end up having to store pureed baby food and breast milk ready for when their infant wants to be fed.
While plastic containers are cheaper, it is safer to store food in glass as it is a non-reactive, non-toxic inert material that will not react with food whether hot or cold. Some plastics by contrast leach chemicals into food when heated.
The other advantage of glass containers is that they don't get stained by the food stored in them.
This page lists the glass containers for baby food.