Testnet is a version of the Stellar network, which is used for development. The network sometimes resets, so the lumens here have no value.
Enable Testnet Feature
- Go to main settings (click the “setting” icon on the top right corner of the main menu).
- Toggle the switch next to "Show Testnet Accounts" to activate the testnet option.
- Select the arrow next to "Settings" to go back to the main page.
- Now when you're back on the main page, the button "Switch to Testnet" would appear next to the setting button. Select "Switch to Testnet" to go to testnet.
- To go back to "mainnet" or to leave testnet, select the "Switch to Mainnet" button next to the setting button.
Friendbot is a tool on the Stellar testnet, which gives you free testnet lumens. Friendly, indeed.