1, the main board. Motherboard is a platform for the work of the various parts of the computer, it is closely connected to the various parts of the computer together, the various components through the motherboard for data transmission. That is to say, the computer is an important transportation hub in the motherboard, the stability of its work affects the stability of the whole machine.
2, CPU. CPU is the central processing unit, which is the core and the control core of a computer. Its function is mainly to explain the computer instructions and the data processing computer software. CPU consists of an arithmetic unit, a controller, a register, a cache, and the data, control, and the state of the connection between the data, the control, and the status of the bus. As the core of the whole system, CPU is the highest executive unit of the whole system, so CPU has become the core component of the computer performance, many users have to judge the grade of the computer as a standard.
3, memory. Memory is also called internal memory or random access memory (RAM), divided into DDR SDRAM and SDRAM memory, but SDRAM because of low capacity, slow storage speed, poor stability, has been out of the DDR) memory belonging to the electronic storage device, which is composed of a circuit board and chip, is characterized by small size, speed, electricity can be saved, empty without electricity, that is, the computer is in the boot state memory can store data, after the shutdown will be all of the data is automatically cleared. Ram has DDR, II DDR, III DDR three categories, capacity 1-64GB.
4, hard disk. Hard disk belongs to external memory, mechanical hard disk is made by the metal disk, and magnetic sheets are memory function, so storage to disk on data, whether in the boot or shutdown, all is not lost. Hard capacity is very large, has reached TB level, the size of 3.5, 2.5, 1.8, 1 inches, the interface has IDE, SATA, SCSI, SATA, the most common. Mobile hard disk is a hard disk as a storage medium, emphasizing the portability of storage products. On the market the vast majority of mobile hard disk is a standard hard drive based, and only a small part is to micro drive (1.8 Inch hard disk, etc.) as the foundation, but price factors determines the mainstream mobile hard disk or standard laptop hard drive based. Because the hard disk is used as a storage medium, the reading and writing mode of the data of the mobile hard disk is the same as the standard IDE hard disk. Mobile hard disk with USB, IEEE1394, and other fast transmission speed interface, can be high speed and system data transmission. A hard disk, composed of a control unit and a memory unit (FLASH chip), is a solid state electronic memory chip. Solid state hard disk in the product appearance and size are completely consistent with the general hard disk but the solid hard disk faster than the mechanical hard drive.
5, graphics cards. Graphics at work and display with output graphics, text, the role is computer system need to display information to convert the drive, and displays to provide line scanning signal and control the display of the display correctly, is connected to the display and the personal computer motherboard important element, man-machine conversation is one of the most important equipment.
電腦主機的五大硬件壹般是指：主板、CPU、內存條、硬盤、顯卡。這五大件直接影響電腦的性能。
1、主板。主板是電腦中各個部件工作的壹個平臺，它把電腦的各個部件緊密連接在壹起，各個部件通過主板進行數據傳輸。也就是說，電腦中重要的“交通樞紐”都在主板上，它工作的穩定性影響著整機工作的穩定性。
2、CPU。CPU即中央處理器，是壹臺計算機的運算核心和控制核心。其功能主要是解釋計算機指令以及處理計算機軟件中的數據。CPU由運算器、控制器、寄存器、高速緩存及實現它們之間聯系的數據、控制及狀態的總線構成。作為整個系統的核心，CPU也是整個系統最高的執行單元，因此CPU已成為決定電腦性能的核心部件，很多用戶都以它為標準來判斷電腦的檔次。
3、內存條。內存又叫內部存儲器或者是隨機存儲器（RAM），分為DDR內存和SDRAM內存，（但是SDRAM由於容量低，存儲速度慢，穩定性差，已經被DDR淘汰了）內存屬於電子式存儲設備，它由電路板和芯片組成，特點是體積小，速度快，有電可存，無電清空，即電腦在開機狀態時內存中可存儲數據，關機後將自動清空其中的所有數據。 內存有DDR、DDR II、DDR III三大類，容量1-64GB。
4、硬盤。硬盤屬於外部存儲器，機械硬盤由金屬磁片制成，而磁片有記憶功能，所以儲到磁片上的數據，不論在開機，還是關機，都不會丟失。硬盤容量很大，已達TB級，尺寸有3.5、2.5、1.8、1.0英寸等，接口有IDE、SATA、SCSI等，SATA最普遍。移動硬盤是以硬盤為存儲介質，強調便攜性的存儲產品。市場上絕大多數的移動硬盤都是以標準硬盤為基礎的，而只有很少部分的是以微型硬盤（1.8英寸硬盤等）為基礎，但價格因素決定著主流移動硬盤還是以標準筆記本硬盤為基礎。因為采用硬盤為存儲介質，因此移動硬盤在數據的讀寫模式與標準IDE硬盤是相同的。移動硬盤多采用USB、IEEE1394等傳輸速度較快的接口，可以較高的速度與系統進行數據傳輸。固態硬盤用固態電子存儲芯片陣列而制成的硬盤，由控制單元和存儲單元（FLASH芯片）組成。固態硬盤在產品外形和尺寸上也完全與普通硬盤壹致但是固態硬盤比機械硬盤速度更快。
5、顯卡。顯卡在工作時與顯示器配合輸出圖形、文字，作用是將計算機系統所需要的顯示信息進行轉換驅動，並向顯示器提供行掃描信號，控制顯示器的正確顯示，是連接顯示器和個人電腦主板的重要元件，是“人機對話”的重要設備之壹。