Tech in Diagrams

What is a Computer?

A computer takes input, processes it with a CPU using memory, keeps results in storage and returns output.

Beginner 4 min IT Fundamentals
Input · process · store · output
  • Data in / out
  • Processing
  • Instructions / files
You open a photoKeyboard, touch, a clickall arrive as dataINSTRUCTIONSThe programload · read · drawSoftware decides whatthe hardware does nextWORKING MEMORYRAM— in use right nowcleared on power offPROCESSORCPUexecutes instructionsMOTHERBOARD · BUS — HOW THE PARTS EXCHANGE DATA0100 1101PERSISTENT STORAGEStorageFiles, apps and settings stayhere whether the machine ison or off.open = copy into RAMOUTPUTThe photo appearsPixels, sound, a saved fileRAM VS STORAGEPOWER OFFRAM clears · storage keeps filesUnsaved work lived only in memory.Saving is what writes it to storage.
One action followed all the way through: input arrives, memory holds what is active, the processor works through instructions, storage keeps what must survive the power going off, and the result leaves as output.

Hover input, memory, the processor, the bus or storage to isolate its path; click any component for a short explanation.

What you are looking at

The same five roles exist in a phone, a laptop and a rack server — only the scale differs.

Memory is fast but temporary; storage is slower but keeps data without power.

Why it matters

  • Almost every performance problem traces back to one of these parts: not enough CPU, not enough memory, or slow storage.
Next conceptWhat is an Operating System?An operating system sits between applications and hardware, sharing the machine safely between programs.