"Storage" is the general sense of storing something away. "A warehouse" is a physical building.

warehouse is either a verb; if you add (to) before it or (ing) , (ed) for past tense , or if in a context of a noun: a building; then the verb influences the noun in meaning, therfore the "item (s)" in question is "staged" in a storage location to be taken out to be "use", "sold" or deployed for future, this is the subtle difference between storage and warehouse, However, the word storage is only a noun, which should not be confuse with the verb "store" or to store something, which is further confused by the same noun in which products are sold. Now taking it further, in the sense that you are trying to compare the two, the distinction, is a matter of permanence, I can associate archiving data with storing ( which can mean disorganized or organized)in general. more permanent, in comparison to warehouse to me meaning a staging area structured, organised and inventoried for future access