Whenever a website is hosted, it is available worldwide as the Internet has worldwide reach. So that website can be available from anywhere, but the network connections can be (marginally) slower from certain parts of the world. For that reason, the highly trafficked websites use a CDN, which basically adds server closer to the end-users to mitigate slower network connections. However, a CDN can only serve static content like images or webpages with a low change rate, so it will not work for dynamic websites such as CiviCRM, where the data must be fetched from the database on each page view.
So in your case the main issue is not so much going to be reachability or trans-continent connection speed, but really local Internet access. If local Internet access is poor, your end-users will have a slower access to your CiviCRM website wherever it is hosted. And finding good Internet access in parts of Africa or Latin America is often very difficult.
About 'cloud hosting', this is really a buzz word that does not mean anything, everyone does cloud hosting.
Feel free to call cividesk at +1 (720) 381-3939 for any questions you might have related to hosting. Our service includes everything from hosting, software maintenance including upgrades, fixes for CiviCRM issues, end-user support and mentoring.