Where and wherever differ in meaning as well as use in sentences.
Difference in meaning
Wherever refers to a non-specific place or direction; where refers to a specific place or direction. Examples:
Where ignorance prevails, knowledge spreads. [Ignorance prevails at a specific place, say organizations with inept leadership.]
Wherever ignorance prevails, knowledge spreads. [Ignorance can prevail anywhere.]
Where the rain poured heavily, the children danced and played joyfully. [Rain poured heavily at a specific place, say in my locality.]
Wherever the rain poured heavily, the children danced and played joyfully. [The rain could’ve poured heavily anywhere.]
The hyenas went where the scent of a kill took them. [So far, we’ve looked at examples of specific or non-specific place. Here, it’s a specific direction.]
The fish swim wherever the current flows. [Non-specific direction]
Though rarely, wherever can be used in place of where to add emphasis – and sometimes surprise as well. Examples:
Where did you hear that rumor?
Wherever did you hear that rumor! [Wherever lends emphasis – and surprise (note the exclamation sign).]
Where does he get the energy to work such long hours and still stay active?
Wherever does he get the energy to work such long hours and still stay active?
Difference in use
They’re used differently in sentences, while retaining their meaning of specific and non-specific.
In independent clauses
Where is used as an interrogative adverb in independent clauses. Wherever though is rarely used in such way. Examples:
Where can I buy fresh produce around here? [As interrogative adverb]
In dependent clauses
Where can introduce noun, relative, and adverb clause, functioning as interrogative adverb, relative adverb, and subordinating conjunction, respectively. Wherever can introduce adverb clause, functioning as subordinating conjunction. Examples:
Where they plan to hold the meeting has not been decided yet. [As interrogative adverb in noun clause]
The town where I grew up has changed a lot over the years. [As relative adverb in relative clause]
Where the two paths meet, there’s a beautiful garden. [As subordinating conjunction in adverb clause]
Wherever you go, you’ll find people who speak English. [As subordinating conjunction in adverb clause]
As subordinating conjunction, only where can be pre-modified by focusing adverbs such as just, right, only, exactly, precisely, simply, specifically, and strictly. Examples:
Just where the two paths meet, there’s a beautiful garden.
Just wherever you go, you’ll find people who speak English. [Incorrect]