Do you mean between Java SE 6 in Dec. 2006 and Java SE 7 in 2011?
I remember being taught using 6 in high school around 2009.
I remember being taught using 6 in high school around 2009.
There were very many important changes in the meantime over that timeframe, but generics and lambdas fundamentally changed how you use the language - Java 4 is not the same language as 5, same between 7 and 8. This is not the case for the 6 and 7 releases.