Samurai and knights were very different in many ways but also in some ways the same my point is proven down below.
Knights and samurai knights first appeared in 11th century samurai appeared in the 12th century.
They both also had codes of conduct.
How ever the codes of conducts were mostly different samurai would kill them self's if their lord died knights how ever did not.
Samurai and knights were at around the same place in their country's social order they were both the warriors of their country.
Their training started around the same age but ended with a few years difference samurais training ended at the age of 14 when knights training ended at the age of 21.
They appeared in very different places samurai appeared on an archipelago that was mountainous knights how ever appeared on the main land of England on relatively flattish terrain.
When they stopped being used Knights went out of use in the 1600 samurai went out of use in 1868.
Samurai had a katana and metal scales as armor knights how ever had a heavy full body suit and a sword.
Did you know that the makeup female samurais used contained dangerously high amounts of lead also did you know that knights had their squires server them meals and drinks.