# 📦 Linux Libraries & Package Management

This guide provides a quick overview of **library types**, **package sources**, and **Debian-based package management** commands using `apt`.

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## 📚 Library Types

Linux supports two main types of libraries:

1. **Static Libraries (`.a`)**  
   - Linked at **compile-time**  
   - Included in the final binary  
   - Larger file size, faster execution

2. **Shared Libraries (`.so`)**  
   - Linked at **run-time**  
   - Saved separately from the binary  
   - Saves space and allows updates without recompiling

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## 📦 Package Sources

### ✅ Official Packages  
Provided and maintained by the distribution (e.g., Debian, Ubuntu, Red Hat).

### 🌐 Third-Party Packages  
Created by external developers or organizations. Use with caution and verify trustworthiness.

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## 🏬 Linux Package Managers

### 📦 Debian-based Systems
- **Package Manager**: `apt`
- **Low-level Tool**: `dpkg`
- **Package Format**: `.deb`

### 📦 Red Hat-based Systems
- **Package Manager**: `yum` or `dnf` (newer)
- **Low-level Tool**: `rpm`
- **Package Format**: `.rpm`

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## 🌍 Package Mirrors

Mirrors are alternative download sources for package repositories, often closer geographically for faster updates.

To sync with package mirrors and get the latest updates:

```bash
sudo apt update
```

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## 🔧 Common `apt` Commands

| Command                  | Description                           |
|--------------------------|---------------------------------------|
| `apt update`             | Refresh package lists                 |
| `apt upgrade`            | Upgrade all installed packages        |
| `apt list`               | List packages                         |
| `apt show <package>`     | Show details of a package             |
| `apt install <package>`  | Install a new package                 |
| `apt reinstall <package>`| Reinstall an existing package         |
| `apt remove <package>`   | Remove a package (keep config files)  |
| `apt purge <package>`    | Remove package **and** config files   |
| `apt-cache search <term>`| Search for a package                  |
| `apt autoremove`         | Remove unused dependencies            |

> 🔐 Use `sudo` before these commands when required.