A checker is used to check whether a given transaction has taken place correctly .
This may include data correctness and correct signalling order.
A Scoreboard is used to keep track of how many transactions were initiated, how many finished and how many are pending and whether a
given transaction passed or failed.
To find the differences between scoreboard and checker we have to understand the meaning of transaction:
"The transaction is quantum of activity that occurs in design bounded by time"
"A transaction is a single transfer of control or data between 2 entities"
"A transaction is a function call"
More on checker:
checker,endchecker are sv constructs refer sv 1800-2009 LRM section-17 .
checker is a place holder for assertions. LRM says
“The checker construct in SystemVerilog was specifically created to represent such verification blocks encapsulating assertions along with the modeling
code. The intended use of checkers is to serve as verification library units, or as building blocks for creating
abstract auxiliary models used in formal verification.”
