on-call和standby在多数情况下意思相同，都是指雇主要求雇员待命，接到电话或通知随时到岗。比如在捷克共和国：

On-call or “standby” duty is defined by the new Labour Code, valid from 1 January 2007, as a period during which an employee is in a state of readiness to perform work, as set out in his or her employment contract. It relates to work that must be done in addition to the employee’s normal work schedule in the event of urgent need. The employee must be on standby at a location agreed with that employee, which must not be the employer’s workplace. On-call duty is considered as working time.

但在一些国家，这两个概念有区别。On-call是指工人待在家里（或自己选择的地方），随时等待电话通知，如有工作，随时到岗。Standby（“站在旁边”），是指工人在工作场所或指定场所等待，随时待命。在德国：

No statutory definition of on-call duty exists, but the Federal Labour Court has defined it as a “background service”, whereby employees have to be available by telephone contract to be called on to work at a place of their choice, which they must indicate to the employer. This is in contrast to standby duty, whereby employees have to be available at a place designated by the employer.

对于翻译而言，如果on-call和standby无区别，则可以都翻译为“待命”。如果有区别，也可以把前者翻译为“电话待命”，后者翻译为“现场待命”。

另外，在荷兰有on-call contract待命合同的概念，包括两种，第一种属于“劳动合同”，规定雇员平时不工作，仅在电话通知时工作。如果双方在合同中商定了最多和最少的工作时数，就叫“min/max”contract（“最多/最少工时”合同）；不保证工时，则叫作“zero hours”contract（“零工时”合同）。第二种待命合同叫作framework agreement（框架合同），只规定工作条件（working conditions），不规定工时（working hours）。每次雇主有工作时打电话，再签订一个固定期限合同（fixed term employment contract）。