What is the meaning of the Hadith classification "Hasan Gharib" and what are the ranks of Hadiths that are permissible to use as evidence?

The answer discusses the ranks of Hadith and its various classifications according to several considerations:

1. Regarding who the Hadith is attributed to: Marfu‘ (elevated): The words of the Prophet, peace be upon him. Mawquf (stopped): The words of a Companion. Maqtu‘ (severed): The words of a Tabi‘i (successor).

2. Regarding the chains of transmission (Turuq) and Sanads of the Hadith: Mutawatir (consecutively recurrent): Came through very many chains and narrations. Ahad (single-chain) (or Gharib - strange/unique): Came through a single chain or narration. It may be absolutely unique (only one chain) or relatively unique (unique in relation to a specific narration).

3. Regarding the ruling on the Hadith (acceptance and rejection): Maqbul (acceptable): That which meets the conditions of acceptance and can be used as evidence. It is divided into: Sahih (authentic): Meets the highest conditions of acceptance. Hasan (good): Meets the lowest conditions of acceptance. Mardud (rejected): That which does not meet the conditions of acceptance. It is divided into: Da‘if (weak): Failed to meet one of the conditions of acceptance. Mawdu‘ (fabricated): Its chain of transmission includes a liar or someone accused of lying. It is mentioned that there are sometimes synonymous terms used, such as "Jayyid" (good) for Hasan, and "Batil" (false) for very weak. It also clarifies the meaning of Imam Al-Tirmidhi’s saying "Hadith Hasan Gharib," which means that the Hadith is Hasan in terms of acceptance and rejection, and Gharib in terms of its chains of transmission, and the uniqueness may be relative.