What is the difference between popd and cd -?

The popd and cd - commands are both used for navigating directories in the terminal, but they serve different purposes and operate in different ways:

popd

• Function: popd is used to return to the previous directory saved on the directory stack, which is managed by pushd.
• Stack Management: When you use pushd, it saves the current directory on a stack. popd removes the top directory from the stack and changes to that directory.
• Usage: It is primarily used in conjunction with pushd to manage multiple directories.
• Example:

  pushd /path/to/dir1  # Stack: /home/user -> /path/to/dir1
  pushd /path/to/dir2  # Stack: /path/to/dir1 -> /path/to/dir2
  popd                  # Returns to /path/to/dir1

cd -

• Function: cd - is used to switch back to the last directory you were in, regardless of whether it was saved on a stack.
• No Stack Management: It does not manage a stack of directories; it simply toggles between the current directory and the last one.
• Usage: It is useful for quickly switching back and forth between two directories.
• Example:

  cd /path/to/dir1
  cd /path/to/dir2
  cd -  # Returns to /path/to/dir1

Summary of Differences:

• Stack vs. Toggle: popd works with a stack of directories created by pushd, while cd - toggles between the last two directories without a stack.
• Use Cases: Use popd when managing multiple directories with pushd, and use cd - for quick navigation between two directories.