You can use templates to generate different types of capture notes, and to store them in different places. For example, if you would like to store new tasks under a heading ‘Tasks’ in file TODO.org, and journal entries in a date tree in journal.org you could use:
(setq org-capture-templates '(("t" "Todo" entry (file+headline "~/org/gtd.org" "Tasks") "* TODO %?\n %i\n %a") ("j" "Journal" entry (file+datetree "~/org/journal.org") "* %?\nEntered on %U\n %i\n %a")))
In these entries, the first string is the key to reach the template, the second is a short description. Then follows the type of the entry and a definition of the target location for storing the note. Finally, the template itself, a string with %-escapes to fill in information based on time and context.
When you call M-x org-capture, Org will prompt for a key to select the template (if you have more than one template) and then prepare the buffer like
* TODO [[file:link to where you were when initiating capture]]
During expansion of the template, special %-escapes1 allow dynamic insertion of content. Here is a small selection of the possibilities, consult the manual for more.
%a annotation, normally the link created with
org-store-link%i initial content, the region when capture is called with C-u. %t timestamp, date only %T timestamp with date and time %u, %U like the above, but inactive timestamps
 If you need one of these sequences literally, escape the % with a backslash.