Nrog rau kev loj hlob sai ntawm kev lag luam kev lag luam thiab kev vam meej ntawm kev tshawb fawb thiab thev naus laus zis, kev lag luam hauv computer tau txhim kho sai, thiab cov ntaub ntawv xov xwm raws li computer thiab kev sib txuas lus thev naus laus zis yog nyob rau lub sijhawm ntawm kev loj hlob. Nrog rau kev txhim kho tseem ceeb ntawm kev lag luam thiab kev coj noj coj ua, tib neeg cov kev xav tau rau lub neej zoo thiab ib puag ncig kev ua haujlwm kuj nce ntxiv. Cov kab ntau lawm kuj tau pib siv computer los txhim kho kev ua tau zoo thiab raug. Cov kab ntau lawm kev ua haujlwm phau ntawv yog qhov tseem ceeb rau qee cov kab sib dhos ua ke vim tias lawv cia siab rau kev siv tes ua haujlwm rau kev ua haujlwm. Tag nrho cov txheej txheem ua haujlwm yog los ntawm cov lus qhia tshwj xeeb ntawm phau ntawv ua haujlwm ntau lawm. Tam sim no, phau ntawv qhia kev ua haujlwm dav dav tau muab tso rau ntawm qhov sib dhos khib ntawm cov kab ntau lawm, thiab nws tau txiav txim siab tias cov ntawv qhia ua haujlwm sib txawv yuav muab tso rau hauv txhua qhov chaw ua haujlwm. Qhov tsis zoo ntawm kev tso cov khoom lag luam ib txwm siv rau ntawm cov khoom sib dhos racks yog raws li hauv qab no:
1. Cov ntawv pov tseg tsis yog ib puag ncig zoo.
2. Yuav tsum hloov phau ntawv hloov tsis zoo.
3. Nws yooj yim ua yuam kev thaum hloov cov xov hlau.
4. Kev tswj cov ntaub ntawv tsis zoo.