A project can have a set of properties. These might be set in the buildfile by the property task, or might be set outside Ant. A property has a name and a value; the name is case-sensitive. Properties may be used in the value of task attributes. This is done by placing the property name between "${" and "}" in the attribute value. For example, if there is a "builddir" property with the value "build", then this could be used in an attribute like this: ${builddir}/classes. This is resolved at run-time as build/classes.