What is the difference between lockout and tagout?

The two devices have very similar effects, but are very different when it comes to a flourishing LOTO program

All LOTO programs know the terms lockout and tagout, but what's the fundamental difference between the two? 

Lockout refers to a device that holds hazardous energy in isolation and prevents machines from being energized with physical restraints that cannot be removed without a key. 

Tagout devices warn employees against reenergizing while they are being serviced. They are simply much easier to remove and do not offer the same level of protection.