# Enabling object lock

Object lock can prevent objects from being removed or overwritten for a specified period. Note that you must first enable versioning before enabling this feature on a bucket. Unlike versioning, object lock must be enabled at the time of bucket creation and the settings cannot be changed after creation.

You can either choose to define a retention period for each object individually or for all underlying objects. Legal holds can only be defined by version or object and not by bucket.

* **Reserve the option for individual retention periods** for underlying objects by leaving the 'Retention' checkmark blank.

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* **Set up aggregate retention periods** for all underlying objects by defining the retention mode and validity when creating the bucket.

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