There are four different types of potting soils: all purpose, premium, professional and plant specific.
All-purpose potting soil is appropriate for adding ingredients, such as plant food (fertilizer). The type of fertilizer you use largely depends on what plants you're planting. What plants are you planting?
Premium mixes help augment water drainage and aeration with the addition of perlite and vermiculite. Some premium mixes include water-soluble or slow-release fertilizer. The bag of "TLC premium potting soil" should say if it contains fertilizer or not.
Professional mixes contain materials that are more completely processed and are usually very high quality.
Plant-specific soils are premium mixes designed specifically for a certain plant's needs, such as cactus or African violets.
