Concept: ergative alignment

Definition

[[Ergative alignment is an argument coding pattern where the S-argument of intransitive verbs has the same argument coding as the P-argument of transitive verbs but different coding from the A-argument.]]

Croft's comparative concept
ergative alignment (system) (STR):

ergative alignment system (STR) = a system in which the S and P roles are expressed with the same form, but the A role is expressed with a different form. Example: in Yuwaalaraay, argument phrases expressing the A role use the Ergative flag -gu, but argument phrases expressing both the S and P roles use the zero-coded Absolutive flag. (Section 6.3.1)

Wikipedia
ergative–absolutive alignment