Please clarify the difference between ‘Ulumul Hadith and Usulul Hadith.
Technically, ‘Ulumul Hadith refers to the branches of Hadith sciences.
Whilst Usulul Hadith [also known as Mustalahul Hadith] is the study of the terminologies of these branches of Hadith sciences.
These terms are also used interchangeably to refer to the various branches of the sciences of Hadith and their related terminologies.
Refer: (Lamahat min tarikhis sunnah, pg.219)
And Allah Ta’ala Knows best,
Answered by: Moulana Muhammad Abasoomar