In a laptop you use SODIMM memory modules. This memory is smaller than the ram modules that you install in a desktop computer. You can also find the memory that is currently installed via task management in Windows and in Linux by executing the command 'dmidecode --type 17'.
The memory for your laptop must also match the memory that is now in your computer. For example, you buy DDR4 SODIMM memory at a speed of 2133 MHz if it is now installed in your laptop. Checking how much space is left in your laptop can be difficult. Also remember that the difficulty of replacing memory in your laptop can vary greatly between different types and brands.