Why[]
DNS Caching is important because it allows us to save a lot of time on DNS lookups
What[]
DNS Caching is the process of saving the results of DNS queries at the local DNS servers so that we don't need to run the entire query process every time we want a new domain.
How[]
Positive Caching[]
Local DNS servers store the result of DNS queries and it holds it for a time based on a TTL value and these records are deleted after TTL expires
Negative Caching[]
Remember what doesn't work and do a short circuit when a future DNS query for the same domain happens. This is not as common and is not always implemented