Great question! There is very little difference between the two words. Both words have the same meaning. Rarely - Is an adverb it means on very few occasions; almost never: example - I rarely wear the color purple. Seldom - Is an adverb - it means almost never It can be used more formally than rarely example: Seldom do I hear from my cousin in France. I hope this was helpful ;-)

very little difference in meaning, however rarely is used much more.. seldom can perhaps be interpreted as 'very rarely', but essentially the difference is negligible.

They are often interchangeable but 'rarely' is more common. "I rarely go to the coffee shop." "Seldom do I go to the coffee shop."

some schools of thought say Seldom 10%-20% of the time Rarely - less than 10%