Explanation

Box 1: Strong
Strong: Strong consistency offers a linearizability guarantee. The reads are guaranteed to return the most recent committed version of an item. A client never sees an uncommitted or partial write. Users are always guaranteed to read the latest committed write.
Box 2: Bounded staleness
Bounded staleness: The reads are guaranteed to honor the consistent-prefix guarantee. The reads might lag behind writes by at most "K" versions (that is "updates") of an item or by "t" time interval. When you choose bounded staleness, the "staleness" can be configured in two ways:
The number of versions (K) of the item
The time interval (t) by which the reads might lag behind the writes
Box 3: Eventual
Eventual: There's no ordering guarantee for reads. In the absence of any further writes, the replicas eventually converge.