E-Wallet is a way to store and manage money in an account linked to a mobile phone, similar to a bank account. E-Wallet users can send money to other people, pay bills, and purchase many things, including mobile airtime.
Mobile Top Up (also known as talk-time or mobile credit) is used to make phone-calls, send texts, or use data. Mobile Top Up cannot be used as money to purchase other items or pay bills, etc.