Connections are linkages among concepts and experiences. Patterns are repeated/regular/sequence discernable in certain situations.
For instance, if you learn about the 2007-2008 financial crisis, several factors are at play here. Subprime lending, housing bubble, easy credit conditions, etc. Cognitive structures can help you find the connections between all these factors.
A financial crisis happens not just once; it happens multiple times. Cognitive structures can help you spot similarities between those financial crises, thus allowing you to spot a pattern.