The Abhidhammattha Sangaha by Ācariya Anuruddha is a "Compendium of Buddhist Philosophy" and contains the essence of all original seven books of the Abhidhamma-Piṭaka and its traditional commentaries in a systematic, condensed way. So it gives a wide overview of all Abhidhamma. The language is mostly reduced to formulas and sometimes stanzas, so the reader often has to complement important components. Understanding often is impossible without further commentaries or explanation under the guidance of a teacher.

The title of the book, 'Abhidhammattha-Saṅgaha', literally means: 'Summary, abstract or compendium of the realities'. Abhidhammattha, indeed exactly abhidhammattha-dhamma, should be understood in the sense of paramattha-dhamma, e.g. 'in highest sense or ultimate (real) things' - like for example all bodily and mental phenomena of existence - in contrary to the so-called 'conventional things' (paññatti, vohāra-dhamma) which do not possess reality in the highest sense, like for example I, person, man, woman, dog, house, etc.

The follwing translations of the Abhidhammattha-Sangaha are available on the Internet:
Nārada Mahāthera: A Manual of Abhidhamma.
Bhikhu Bodhi (general editor) with tables by Sayadaw U Sīlānanda and explanatory guide by Sayadaw Dr. Rewata Dhamma: A Comprehensive Manual of Abhidhamma

A good idea what the Abhidhamma comprises gives the list of contents of the Abhidhammattha Sangaha:
  • Consciousness (89 or 121 types and classification)

  • Mental factors (52 types, classification and possibilities of combination for a mental unit)

  • Miscellaneous (types of consciousness and feelings, roots, functions, doors, objects, sense-bases)

  • Mental process (working of our mind)

  • Process-freed (death, rebirth, life-continuum, kamma, planes of existence)

  • Matter or physical phenomena and Nibbāna

  • Various categories and groupings

  • Conditionality: Dependent origination (Paṭiccasamuppāda) and Conditional relations (Paṭṭhāna); concepts and human characters (puggalapaññatti)

  • Meditation-subjects and individual suitability.