Operating systems, for personal computers or digital devices, try to do more and more for you, often in the background, without you even being aware of it. Sometimes they do too much, which can cause problems.

iOS 8, the popular operating system for Apple's iPhones, iPads, and iPods, is no exception. It does so much in the background it can prevent you from using your phone throughout the day on a single charge, cause you to have cell data overages your phone carrier charges you for, and compromise your privacy.

Fortunately, you can make changes in the device's settings that prevent such problems. Apple, like other operating-system makers, isn't trying to cause problems. It sometimes just tries too hard to be helpful.

The following suggestions apply to iPhones, with similar procedures available as options for iPads and iPods. None of these suggestions are mandatory. Some of these settings changes have the potential to cause problems of their own, though they easily can be reversed. Often, the same settings change can provide benefits in two or more of the areas of battery usage, data usage, and privacy.

• Use Wi-Fi transfer instead of cell transfer whenever Wi-Fi is available. Wi-Fi transfer doesn't count against your data usage. Do this for each Wi-Fi network you regularly have access to, such as your house or apartment, the library, the coffeehouse, and so on. When you're near such Wi-Fi access, press Settings, Wi-Fi, and under CHOOSE A NETWORK, press the particular Wi-Fi network. If that Wi-Fi network requires a password, type it in. After that, your phone will automatically default to Wi-Fi transfers when you're within access of that Wi-Fi hotspot. You'll know you're using Wi-Fi if you see in the upper-left of your Phone's screen a little radio icon (instead of LTE, 3G, and so on, which mean you're doing cell transfers) to the right of the name of your cellular carrier.
• Delete apps you don't use that are battery hogs, or change the settings of battery-hogging apps you do use. Press Settings, General,Usage, and Battery Usage.One way to change the settings of useful battery-hogging apps is to turnoff background data use. Press Settings, General, Background AppRefresh, then turn the setting to off for those apps that don't needcontinually downloaded data in the background by sliding to the left.
• Delete apps that are storage hogs. Press Settings, General, Usage, Manage Storage. Similarly, delete photos and especially videos that you never look at.
• Turn off Location Services for those apps that don't need to know where you are all the time. Press Settings, Privacy, and Location Services. Some apps, such as Google Maps and Safari, give you a "While Using" option, which can be better than "Always" or "Never." Other apps prompt you to enable Location Services when you load them. I keep only the Weather and Maps apps at "Always" under Location Services.
• Choose which apps you want to automatically have access to your photos. Press Settings, Privacy, and Photos, and slide off those appsthat don't need it.
• Limit Spotlight crawling. Spotlight lets you search for anything on your phone by touching your finger to the screen and dragging down. But many people never use it. Press Settings, General, and Spotlight Search, and uncheck the items you don't want indexed.
• Stop push email. You might not need your phone to continually grab email in the background. Press Settings, then Mail, Contacts, Calendars, then Fetch New Data. Slide Push to off, and under Fetch, push Manually.
• Limit advertisers ability to track you. First, press Settings, Privacy, Location Services, and System Services, and slide Location-Based iAds to the left. Second, press Settings, Privacy, Advertising, and slide Limit Ad Tracking to the right. Third, press Settings, Safari and slide Do Not Track to the right. Also, if it's not already enabled, slide Block Pop-ups to the right, and slide Frequent Locations to off.
• Find out which apps are using your location without your knowing. Press Settings, Privacy, Location Services, and System Services, and slide Status Bar Icon to the right.
• Turn off "parallax," which just gives your phone's interface a 3D look. Press Settings, General, Accessibility, and Reduce Motion, and turn it on.

If you're experiencing performance problems, sometimes all you need is a reboot. To do a hard restart, press the Power and Home buttons simultaneously.