Computer memory has two meanings. Physical memory is the space on your hard drive that determines how many files can be stored on your computer. Random access memory (RAM) for the most part determines the speed of a computer. Both types of memory can be easily checked whether you are a Mac or Windows user.
Steps
Method 1 of 4: Checking Physical Memory on Windows

Step 1. Physical memory is the amount of space on your computer
Physical memory has a lot in common with a USB flash drive or hard drive - it can also store music, photos, files, and the like. Physical memory is different from random access memory, or RAM, which is partly responsible for running a computer.
There are two types of memory: physical and random access (RAM). If space on your computer is important to you, check the physical memory. If your computer's speed is important to you, check the RAM

Step 2. Open "My Computer"
Click on the "Start" button in the lower left corner of the screen. Then click on the "My Computer" icon.

Step 3. On the left side of the page, select the hard drive you want to check
When the window opens, locate the "Windows (C:)" drive. This is the most commonly used drive on the system, but check all drives if you wish. Hard drives appear as gray rectangular icons.
If you don't see any drives, click on the triangle next to the My Computer icon

Step 4. Take a look at the information field under the disk to see how much free space is left
You will see the following: "____ GB free from ____ GB"

Step 5. Open Explorer and check the "Properties" of each disk
If you are unable to follow the instructions above, there is another way to test your memory. When you find yourself in the Explorer window, right-click on the drive (C:) and select "Properties". In the next window, you will see the total memory, as well as the amount that is currently in use. If you have multiple drives, check them all.
Method 2 of 4: Check random access memory (RAM) on Windows

Step 1. Click on the "Start" button in the lower left corner of the screen and find "File Explorer"
This is a window for browsing and searching for files. You can also open it by clicking on the "My Computer" icon.

Step 2. Find the "My Computer" icon on the left pane
On the left side of the window, you will see the My Computer or This Computer icon. Right-click on it, and then select the "Properties" option at the very bottom of the list that appears.
- In the center of the window, you will see the inscription "Installed memory (RAM):". This will indicate the amount of RAM on the computer.
- The more RAM you have, the faster your computer will run.

Step 3. The amount of RAM can be checked in another way
Open "Control Panel" from the "Start" menu and select "System and Security". To find out the amount of RAM on your computer, open Control Panel → System and Security → System. You will see the inscription "Installed memory (RAM):".
Method 3 of 4: Checking Physical Memory on Mac

Step 1. Launch Finder and locate your hard drive
Typically, it will be called "Hard Drive". This could also be your drive (C:).

Step 2. Hold down the Control key and click on the disk, then select "Advanced"
If the option is already highlighted, press Command + I (capital "i") to open the Information Panel.

Step 3. Find out the size and remaining disk space
When you open the window, the amount of memory will be listed in gigabytes (GB). This is the amount of storage you have for music, movies, photos, and documents.
Method 4 of 4: Check RAM on Mac

Step 1. Click on the Apple icon in the upper left corner of the window
In Apple devices, it is quite easy to check the random access memory (RAM). RAM refers to the amount of computer memory to carry out momentary tasks. The more RAM, the faster the computer will run.

Step 2. Click on the "About This Mac" option to display the specifications of your computer, including the amount of memory and RAM used
If you don't see the amount of RAM anywhere, click on the "Advanced" option. The unit of measure will be GB (gigabytes). The size of the computer will be in the range from 4 to 16 GB.