Asterisk to call other country

Hello; I’m hoping some could explain to me how can I make phone calls from the US to colombia using asterisk. Do I need to send the PBX to colombia for this task? How can Asterisk help me lower my costs ?
any guides to do this will be appreciated.

thanks!

Your question is about Voice over IP, in general, not about Asterisk. However the first few chapters of Asterisk: The Future of Telephony may give you the basic grounding needed.

Thanks I will check it out.