Data Center Tiers Classification Explained: (Tier 1, 2, 3, 4)
https://phoenixnap.com/blog/data-center-tiers-classification
Tier 2 colocation data centers are more robust than Tier I centers. Tier II does not have complicated Tier 4 data centers are considered "fault tolerant." Unplanned maintenance does not stop the flow of...
Data center - Wikipedia
https://en.wikipedia.org/wiki/Data_center
Tier III: is described as CONCURRENTLY MAINTAINABLE and ensures that ANY component can be taken out of service without affecting production. Tier IV: is described as FAULT TOLERANT allowing...
Tier 3 rules: Which areas are under the harshest Covid restrictions?
https://www.thesun.co.uk/news/13272207/tier-3-rules-areas-covid-restrictions/
Tier 3 measures will be introduced in areas in the East and South East of England while areas in the north will stay put despite a drop in infection rates.
PBIS.org | Tier 3
https://www.pbis.org/pbis/tier-3
Tier 3 practices stem from strong foundations in Tier 1 and Tier 2 supports. With both tiers in place, schools are free to organize individualized teams to support students with more intense needs.