Explain one similarity in the role of serfs and vassals in the feudal system between 600 and 1450?

One similarity is that they both owed service to another person of high status. Serfs owed service to lords because they provided them protection and land. Vassals owed service to kings because they provided them land.

Explanation:

ummm? is that supposed to be a question or a but this is a reason he won re-election

explanation:

"despite progress in the war, lincoln and most political pundits were convinced that he would lose his bid for reelection in 1864. the country was war weary and the democratic party's nominee, george mcclellan, was likely to negotiate a peace treaty with the confederacy if elected." - loc.gov

its many islands, high mountains, and remote peninsulas isolated population centers.