Lub cache yog qhov khoom siv tes ua nruab nrab nrog kev nkag tau sai. Nws muaj cov ntawv luam ntawm cov ntaub ntawv khaws cia rau hauv lub cim xeeb nrog txoj kev nkag tau tsawg kawg, yog li txuag tus neeg siv lub sijhawm.
Lub cache yog qhov cim xeeb nrog kev nkag tau ntau dua, tsim kho kom ceev cov txheej txheem ntawm nkag mus siv cov ntaub ntawv uas nyob ruaj khov hauv cov cim xeeb. Cov ntaub ntawv caching yog siv los ntawm cov khoom siv nyuaj, CPUs, browsers, thiab web servers. Txhua ntawm lawv cuam tshuam nrog ib yam khoom lossis block ntawm cov ntaub ntawv. Txhua ntawm kev nkag tau muaj cov cim uas qhia txog cov lus sib kis ntawm cov ntaub ntawv hauv kab ntawv thiab cov ntawv luam tawm hauv lub cim xeeb tseem ceeb. Thaum tus neeg siv (CPU, web browser, operating system) nkag mus rau cov ntaub ntawv, lub cache tau tshawb xyuas thawj zaug. Yog tias nws muaj cov ntawv sau nrog tus cim uas sib phim lub cim khoom ntawm cov ntaub ntawv xav tau, tom qab ntawv cov ntaub ntawv khaws cia. Thaum cov ntaub ntawv hauv lub cache tau hloov kho, lawv raug hloov kho hauv lub cim xeeb loj. Hauv chav ceev, qhov uas muaj qhov kev sau ntawv tam sim ntawd, txhua qhov kev hloov pauv ua qhov hloov tshiab ntawm cov ntaub ntawv ntawm lub cim xeeb. Hauv kev sau-rov qab (sau rov qab) lub cache, qhov hloov tshiab tshwm sim ntawm cov khoom raug tshem tawm, ntawm cov neeg thov, lossis tsis tseg. Ntau cov qauv ntawm cov chaw nruab nrab muaj lawv tus kheej cov cache kom txo cov txheej txheem kom nkag mus siv cov khoom siv nkag mus siv lub cim xeeb (RAM), uas qeeb qeeb tshaj li kev sau npe Lub CPU cache tau muab faib ua ntau theem (txog 3). Lub cim xeeb ceev tshaj yog suav tias yog thawj theem cache, lossis L1-cache. Nws yog ib feem tseem ceeb ntawm kev tsim, txij li nws tau nyob rau ntawm tib tuag nrog nws thiab yog ib feem ntawm cov haujlwm zoo. L2-cache - cache ntawm qib theem ob, thiab qhov ntsuas tau coj ua tau zoo. Nws feem ntau yog nyob ntawm qhov tuag, zoo li L1, lossis tsis deb ntawm tus tub ntxhais, piv txwv li, hauv lub tshuab ntaus ntawv (hauv cov txheej txheem ua haujlwm). Lub L3 cache tau ceev tshaj plaws thiab feem ntau nyob ntawm tus tub ntxhais CPU, nws yog qeeb qeeb dua lwm lub lev, tab sis nrawm dua qhov kev ua haujlwm ib lub cim xeeb.
