Feeding and fertilizing are the same thing - applying something intended to supply the nutrient needs of plants. The idea of "feeding" plants was invented when fertilizer was accidentally discovered.
Foliar feeding seems odd to me and I haven't yet been convinced there's any benefit. Plants take in oxygen and some moisture through leaves, and nutrients through soil.
Plants in the ground shouldn't need any feeding/fertilizer. Adding compost to the surface around the root zone periodically should be more than sufficient, if you want to coddle them and spend your $ that way at all. Plants can only be as good as the soil in which they're growing. Spending 15 mins hearing about basic soil microbiology can save you a lot of time, worry, $.
https://www.youtube.com/watch?...
