The science of hadith is one of the most honourable and important sciences as we know through it the truthfulness of what was narrated to Messenger of Allah (صلى الله عليه و سلم) whether it is authentic or weak. It’s importance and honorability are due the honorability and importance of it’s target which is the Sunnah of the Messenger (صلى الله عليه و سلم), the second source of the islamic legislation, the words of who doesn’t pronounce any word out of prejudice, it is nothing except a revelation revealed.
And from the most collective and summarized written texts of this field is the text of Nukhbat al-Fikr in Mustalah ahal al-Athar (the top of thinking in the classification of hadith) by the Hafiz Ahmad Ibn Ali Ibn Hajar al-Asqalani ash-Shafi' (رحمه الله‎‎).