fork – create a child

creates by duplicating.
The new is referred to as the child.

The child and the parent run in separate memory spaces.
have the same content

mappings and unmappings performed by one do not affect the other.

The child is an exact duplicate of the parent except for the following:

* The child has its own unique ID

* The child does not inherit its parent’s memory

* resource utilizations are reset to zero in the child.

* The child’s set of pending signals is initially empty

* The child does not inherit adjustments from its parent

* The child does not inherit locks from its parent
(On the other hand, it does inherit description.)

* The child does not inherit timers

The parent and child also differ with respect to the following specific attributes:

* The child does not inherit change notifications from its parent

* the child does not receive a signal when its parent terminates.

Note the following further points:

The child is created. The entire virtual space of the parent is replicated in the child, including the states, condition variables, and other objects; the use may be helpful for dealing with problems that this can cause.

On success, the child is returned in the parent
On failure, no child is created.

There are a number of limits that may trigger this error

An attempt was made to create a child