There're just sort of things that are unexplainable, something that are beyond our understanding. Something that could damage or destroy anything on its path. Sometimes that 'something' just stay passive and does not harm unless provoked or interacted with. These things, as we call them SCP's. Their very own existence must be kept secret to prevent mass panic and related chaos and allow the society to function normally.

These Anomalies must be 'Secured' before anypony knew they even existed.
They must be 'Contained' so we can study their behaviour and activities.
They must be 'Protected' to avoid any harm they might caused to the society.

I welcomed you, to SCP Foundation. Where all anomalies are kept in secret, hidden in plain sight, away from society.