Difference between かくえき(各駅) and ふつう(普通)

Question

Announcement in the train:

この電車は京浜東北線各駅停車(or 電車 not sure)、大宮行きです。  

And Sometimes ふつう(普通) is used instead of かくえき(各駅).
What is the difference in meaning and usage and when one should be preferred over other?

Answer 1

Most of the time, they are the same, but there is sometimes a difference.

普通 = normal
各駅 = every stations

They are both "no extra charge" trains. Compared to 特急 which stops only at big stations and charge extra for getting to your destination faster.

各駅 will obviously stop at every single station. But 普通 might not stop at very small stations which usually don't have their own platforms.