Could someone clarify what is the difference in English between “older brother” and “elder brother” Thanks
Elder- only goes before a noun:
My elder sister
She is elder than me ---------not correct
Older- can do both:
My older sister
She is older than me
Usage note
In comparisons between two persons, elder means “older” but not necessarily “old”: My elder sister is sixteen; my younger, twelve. (Eldest is used when three or more persons are compared: He is the eldest of four brothers.) In other contexts elder does denote relatively advanced age but with the added component of respect for a person’s achievement, as in an elder statesman. If age alone is to be expressed, one should use older or elderly rather than elder: A survey of older Americans; an elderly waiter.·Unlike elder and its related forms, the adjectives old, older, and oldest are applied to things as well as to persons.
To my knowledge ‘elder, eldest’ are only used for siblings or maybe other close relatives in British English. I have read that Americans don’t use it.
In comparisons only old, older, oldest can be used.
‘elder’ can be found in phrases: an elder statesman
The adjective ‘elderly’ and the collective noun ‘the elderly’ refer to relatively old people, the older generation, senior citizens. Maybe it’s only used in BE (?).
Elder is from Middle English eldre, see elder - Wiktionary.
Older is from Old English ald, from Germanic *alđoz ‘grown-up’, see http://en.wiktionary.org/wiki/old
I would say that Elder is archaic and used mostly in the set phrase, elder brother / sister. You can also say, he is the eldest of my children, he is the elder of the two boys. You can talk about church Elders, but not usually in Britain because we don’t know what they are.
Elder is a very uncommon term, at least among people I talk to. We always use the word “older or oldest.” “She is my oldest child. She is older than him.” But, as Helen said, it is used to refer to church Elders, and we do know what they are here in the US. 
Dear Helen and Jillisa,
I am a Christian living in Japan.
We have “church Elders” in our church (Lutheran).
We call them “Choro”（長老）in Japanese.
Choro" means people who are enjoying their longevity.
However, they are not necessarily “old”.
Elder, in the context of the church, doesn’t mean “old.” It has the meaning of one in leadership or some kind of authority. Those in this position are to be full of wisdom and have a servant’s heart.
In the Church of England, the official religion in Britain, and therefore the religion that people belong to who can’t be bothered to comparison shop ;-), we have vicars and bishops (priests) who tell us what to do. So we don’t have Church elders, who are members of the congregation with special authority or influence.
Dear Jillisa
In our church, or in all churches which have "church Elders"in Japan, “church Elders” are chosen
based on exactly what Jillisa explains. “leadership or some kind of authority.”
Sorry, if I confused you about the church system in Japan by introducing the “literal” meaning of “Choro” in Japanese.
By the way, to my knowledge, not so many churches in Japan have their “church Elders”.
Dear Helen,
It is interesting to know the culture through the church system in every country.
I cannot imagine the situation where one certain religion can be official, like England.
(Christians are total minority in Japan. And I am one of them. )