Devi Mahatmyam (देवीमाहात्म्यम्) is a religious text describing about goddess Durga. It is part of the Markandya Purana (मार्कण्डेय पुराण), it start from chapter 81 and end with chapter 93.
Devi Mahatmyam describes the battle between the goddess Durga against the demon Mahishasura. Devi Mahatmyam has total 13 chapters and 700 verses.
Durgā Saptashatī (दुर्गासप्तशती) it is another name for Devi Mahatmyam. It is called as Saptashati because it contain 700 (सप्तशतम्) verses.
Durgā Saptashatī has total 13 chapters and 700 verses.
Caṇḍī Pāṭha (चण्डीपाठः) – It is a prayer to a form of goddess Durga, mentioned in the Devi Mahatmyam . It is mentioned in Devi Mahatmyam chapter 5 verse 16 till verse 80
Durga SaptaShloki (दुर्गा सप्तश्लोकी) – is a collection of seven important slokas from the Devi Mahatmyam . It is called as सप्तश्लोकी , because it have seven verses (सप्त श्लोक )
The verses are taken from Devi Mahatmyam, but there seems to be no particular sequence of it.