Least Privilege
The principle of granting each piece of software only the access it truly needs.
Glossary
Isolation
Keeping parts of a system separated so trouble in one cannot spread to the others.
In one line
Keeping parts of a system separated so trouble in one cannot spread to the others.
Also calledsandboxingcontainment
Isolation is the practice of building walls between components so that a failure stays contained. If one translator stumbles in its own isolated space, the rest of the system can carry on undisturbed. The wall does not prevent the fault; it prevents the fault from spreading.
This is why many modern systems prefer to run drivers at arm's length. A contained failure can simply be restarted; a shared one cannot. Separation turns what might have been a system-wide collapse into a small, local hiccup.
Isolation does cost a little. Passing requests across a wall takes more effort than reaching directly through it, so there is a modest cost in speed. For most parts, that cost is well worth the safety it provides.
The art is deciding where the walls belong. Too few, and a single fault can travel far; too many, and the constant crossing slows everything down. Thoughtful design places strong walls where failures are most likely or most dangerous, and lighter ones elsewhere.
In practice
In practice, isolation is like the watertight compartments in a ship. If one section is breached, sturdy walls keep the water from flooding the rest, and the vessel stays afloat. Software uses the same idea so that one failing part does not sink the whole system.
