Pey (Fey)

Pey and Fey are both derivatives of the same letter and as there is a sofit form of each, you have four different characters derived from the same letter:

Once again, the difference between the two characters is the presence or absence of a dagesh mark. When the dagesh is absent as in the previous screenshot, the character is pronounced as a 'ph' or 'f' as in 'telephone'.

If however the dagesh is present, then the pronunciation is 'p' as in 'park' or 'party':

As suggested, there is also a sofit version of both of these characters that is used at the end of words. This for example is the sofit version of Fey:

Introduction to Reading Hebrew
The first basics
The Hebrew AlephBet
The Letters of the AlephBet
Aleph
Bet (Beyt)
Gimmel
Dalet
Hey
Vav
Zayin
Chet
Tet
Yod
Kaf
Lamed
Mem
Nun
Samekh
Ayin
Pey (Fey)
Tsade (Tsadik)
Qof
Resh
Shin
Tav
The Significance of the Alephbet
The Basics of Hebrew Verbs
The Hebrew Verb Subject
The Hebrew Verb Object
Hebrew Verb Tenses
Hebrew Verb Voices and Moods
Hebrew Verb Participles
The Infinite Verb Version
Hebrew Nouns
Hebrew Noun Constructs
Using Prefixes With Nouns
Hebrew Pronouns
Hebrew Plural Nouns
Hebrew Adjectives
Identifying Hebrew Questions
Adverbs, Prepositions and Conjunctions
Hebrew Reading Conclusion