Garden soil vs compost

[lovingit]

Hi folks, does anyone know the difference between "garden soil" and "compost"?  This is for planting a shrub and tree.  I believe garden soil is soil mixed with fertilizer.  You're suppose to mix it when planting anew tree or shrub but some people said compost works too.  But I'm not sure what compost is used for.  I read the bag and it doesn't look like compost has fertilizer in it like the garden soil does.  Both are for in ground usage (not potting).  So what's the exact difference?

 

[peppy]

Compost has organic matter in it that is used as an amendment in soil. It "feeds" the soil (microbes, worms, whatever else lives there).

Fertilizers are used to supply nutrients directly to the plant. It mostly consists of nitrogen, potassium and phosphorous (usually indicated by 3 numbers in the description: like 5-3-4). You mix it in prior to planting and then apply it again about every month or so.

 

[jyeh74]

So compost doesn't have any fertilizer?

The nursery told us mix "compost" with soil for the shrub.  Not sure why you need compost if your soil is already nice and soft.  Lowes sells "garden soil" which has fertilizer, which I would think it better to plant for the tree, in the beginning stages when it needs nutrients.