free commnad

Linux/Basic Administration/26-free.md

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+## 🖥️ Viewing Memory Usage with `free`
+
+The `free` command shows your system’s memory usage.
+
+```bash
+free
+```
+
+For **human-readable** output (MB, GB, etc.):
+
+```bash
+free -h
+```
+
+**📊 Explanation of columns:**
+
+| Column           | Description                                                        |
+| ---------------- | ------------------------------------------------------------------ |
+| **💾 total**     | Total physical memory (RAM) available in the system.               |
+| **📂 used**      | Memory currently used by processes and the system.                 |
+| **🆓 free**      | Completely unused RAM (not allocated to anything).                 |
+| **🔄 shared**    | Memory shared between multiple processes.                          |
+| **⚡ buff/cache** | Memory used for file buffers and cache to improve performance.     |
+| **✅ available**  | Estimated memory available for starting new apps without swapping. |
+
+💡 **Pro Tip:**
+
+* `✅ available` is more useful than `🆓 free` for knowing how much memory you can actually use, since Linux keeps unused memory in cache for speed.
+