Filesystems

A Linux filesystem is organized as a single tree, starting from one root directory, /, with everything else nested underneath it, unlike Windows there's no separate "C:" drive.

/
├── home/
│   └── ada/       # your personal files usually live here
├── etc/            # system configuration files
├── usr/            # installed programs
└── tmp/            # temporary files, cleared periodically

Navigating

cd /home/ada       # change directory (absolute path, starts with /)
cd Documents       # relative path, relative to where you already are
cd ..              # go up one level
cd ~               # jump to your home directory
ls -la             # list files, including hidden ones (-a) with details (-l)

An absolute path always starts from / and works no matter where you currently are. A relative path is interpreted starting from your current directory, so cd Documents only works if Documents exists right where you're standing.

Managing files

mkdir projects           # create a directory
touch notes.txt          # create an empty file
cp notes.txt backup.txt  # copy
mv notes.txt todo.txt    # rename/move
rm backup.txt            # delete a file
rm -r old_folder         # delete a directory and everything in it (recursive)