Samsung Galaxy Smartphone Quick optimization and battery features and how to use them

Quick optimization
The quick optimization feature improves device performance through the following
actions:

• Identifying apps that use excessive battery power and clearing unneeded items.
• Deleting unnecessary files and closing apps running in the background.
• Scanning for malware.
  To use the quick optimization feature:
  ◌ From Settings, tap Device care > Optimize now

Battery
Review how battery power is used for your various device activities.
◌ From Settings, tap Device care > Battery for the following options:

• Power saving: Save battery life by limiting background network usage,
  syncing, and location checking. Choose from additional power saving
  options to save more power when this mode is enabled.
• Background usage limits: Identify apps that you don’t use often and limit their
  battery usage. To disable this feature, tap Put unused apps to sleep.
• Battery protection: Choose a method to extend the lifespan of your battery.
• Today: Review your recent battery usage by time, app, and service.
• Charging settings: Customize the charging settings for your device.
• Wireless power sharing: Enable wireless charging of supported devices with
  your device’s battery
• Auto dim screen: Dim the screen when battery is below 5%.
• Show battery percentage: Display the battery charge percentage next to
  the battery icon on the Status bar.
• Battery information: Display the battery status and level.