By Fundamental Concept

Arranged:

alphabetically
by jurisdiction
by legal tradition (e.g.: common law / civil law traditions)
by language

Some Fundamental concepts are:

Contract

Tort

Intentional Tort
Negligence

Property

Personal Property (or Portable Property)
Real Property

Fee simple
Fee tail
Tenancy
Fixture
Charge

Intangible Property (or Intellectual Property)

Copyright
Trade Mark
Patent

Crime

Constitution

Statute (Fr: Loi)

Regulation