why put ram in slots 4 and 2

AMBIL SEKARANG

my laptop task manager said i used 1 of 2 ram slot even though im using both slots 4gb x 2 but it reads both, what happened? - Microsoft Q&A

so my task manager said 1 of 2 ram slots used, when i hover it said slot 1: empty slot 2: 4,0GB, 1600mhz but it show 8gb of ram just fine my bro's laptop have both slot used and it said 2 of 4 slot used is this the same case just my task manager only…

Mainboard Gigabyte Z790 Aorus ELITE AX DDR4 (Wifi, ...

Khe cắm RAM: 4 khe (Tối đa 128GB). Khe cắm mở rộng: 1 x PCI Express 5.0 x16 slot, 2 x PCI Express 4.0 x16 slots. Khe cắm ổ cứng: 4 x M.2 slots, 4 x SATA 6Gb/s ...

motherboard with 6 ram slots

Chipset: Intel® Z790 Chipset - Socket: LGA17000 Hỗ trợ CPU intel 12/13/14th - RAM: 4 khe DDR5( Tối đa 192GB) - Kích thước: ATX (30.5 cm x 24.4 cm) - Khe cắm ổ cứng: 5 x M.2 slots and 4 x SATA 6Gb/s ports.