Question

Is current directory same as working directory?

when I start a program under the PATH search folders, will the first folder become its current directory?

Answer 1

Sort of.

There’s one working directory, which is a complete path (including drive letter).

But there is a “current directory” for each drive, which affects drive-relative paths (of the form D:name with no backslash following the drive specification). IIRC, these are stored in the table of environment variables.

The link is that the shell automatically updates a current directory whenever the working directory changes. But other programs don’t necessarily do this.

PATH search has no effect on current directory or working directory. They are inherited from the parent, unless explicitly specified when starting a new process.

See also this related question.