SAP NetWeaver AS ABAP Release 750, ©Copyright 2016 SAP AG. All rights reserved.
ABAP Keyword Documentation → ABAP Glossary →host variable
ABAP data object (usually a variable) specified in an operand position of an Open SQL statement or of a statically embedded Native SQL statement. In Open SQL, a host variable must be prefixed with the escape character @; in Native SQL, with the escape character :. In ADBC, the placeholder ? (to which ABAP data objects are bound) is used instead of host variables.