There are two types of such problems: insufficient storage space and insufficient RAM (random access memory).
Storage space (commonly 64/128/256/512G) stores data and files such as music, pictures, movies, apps and application data of the phone. The larger the storage space, the more apps you can install/store pictures music movies etc.
RAM (commonly 4/6/8/12G) is used to run/process applications. the larger the RAM, the more applications and application processes can be opened at the same time, and the background is not easily cleaned.
Storage space FAQs：
1.Q: Why does the system firmware occupy dozens of GB memory?
A: First, determine whether the phone is really abnormal. For example, occupying hundreds of GB may be caused by system bugs, while occupying 10-30GB may be normal.
The system is also stored in the phone, and needs to occupy the phone storage space to ensure the normal operation of various functions of the phone. The current cell phone system contains more functions, and it is normal for the system firmware to occupy more memory.
2.Q: What is "Other" (Settings-About phone-Storage-Other) inside the phone memory and why does it take up so much space?
A: In the process of using the phone, in addition to the files saved by the user, some software data will be generated, some of these data file formats can be recognized by the system (such as .mp4, .mp3, .jpg and other file formats), but there will be some file types that the system can not recognize the format, these unrecognized files will be categorized as "other files ". To clean up, refer to the article: What are the "Other" in the Storage space of Xiaomi’ phones?
3.Q: How to clean up the phone when the storage space is insufficient?
A: You can go to Security>Cleaner and select Deep clean after cleaning. In this interface, you can clearly see the recommended cleanup items in your phone: "Video, infrequently used applications, installation packages, App data, large files" and so on. Tap them one by one, check the Apps and files you don't use often, and selectively delete them.
4.Q: Does Second space take up storage space?
A: Second space will occupy the storage space of your phone.
RAM FAQs：
1.Q: How can I check the remaining RAM of my phone?
A：Settings---Home screen---Show memory status
2.Q: Why does RAM take up a lot of memory without opening background Apps or with only a few Apps open?
A: The phone is not only open Apps and background Apps occupy RAM, there are also some active App processes, such as App notification process, system basic services, etc. (entering Settings-Apps-Manage apps-Selective App-Force stop, if you can click "Force stop", then the App is a process running). You can reduce these processes by restarting them.
3.Q: Do Dual apps affect the phone's RAM?
A: Dual apps may have a slight impact on RAM.
4.Q: Why do the background Apps on my phone close automatically?
A: When the phone has more background applications or a large amount of calculations, the background application process may be closed to ensure the application usage experience. It is recommended to clean up unnecessary background programs in time to reduce the burden of computing on the phone.
5.Q: How to use the RAM extension on my phone?
A：Refer to the article Memory extension introduction .