Lawful or permissible. The concept of halāl has spiritual overtones. In Islam there are activities, professions, contracts and transactions that are explicitly prohibited (harām) by the Sharīah. All other activities, professions, contracts and transactions are halāl.
The concept of halāl differentiates Islamic economics from conventional economics. In conventional economics all activities are judged on economic utility. In Islamic economics, spiritual and moral factors are also involved, where an activity may be economically sound but may not be allowed if it is forbidden by the Sharīah.