<%= render :partial => 'partial/path', :locals => {:xyz => 'abc'} %>

vs

<%= render :partial => 'partial/path', :object => @some_object %>

:locals => {:xyz => 'abc'} makes the variable xyz available in the partial(and the value is ‘abc’).

using :object will define a variable with the same name as the partial by default.

render :partial => 'account', :object => @some_account

will make sure the account variable in the partial will be set to @some_account. You can rename the variable using the :as option.

The biggest advantage of the :localsis that

1. you have very clear control over the objects and names
2. you can assign more than 1 variable So you could do something like

render partial => ‘some_view’, :locals => { :user => account.user, :details => some_details_we_retrieved } making a clear seperation possible when needed.

The disadvantage of the :locals approach is that it is more verbose, and sometimes a simple

render :partial => 'account'

is identical to

render :partial => 'account', :locals => {:account => @account }

So use the one which suits you the best (or where it suits the best).