I discovered some mysterious directories in my home.
Every one has dot before name.
They can't be seen from file explorer or even terminal, for example I'm using Eclipse "open file" for seeing them.
They are called for example ".arduino", ".mozilla", ".local"...
My question is: What are they? Are they bad? Why are they messing my home? Is it like apps data?
Files with a dot at the beginning of the name are hidden by default. In Nautilus (Ubuntu's default file manager) you can make them visible with Ctrl+H. For the ls command, add the switch -a to it, which lists all files.
These files are either there from the beginning (like .local or .config) or are created by a program to store configuration etc.
As an example, PlayOnLinux stores its virtual drives in ~/.PlayOnLinux. Java will create the .java directory, and Firefox and Thunderbird use the .mozilla directory. There are also files, not only directories. E.g. .bash_history contains the command history of your terminal shell.
So don't worry about these files. As a "normal" user, who doesn't mess with his systems config, you'll most likelynever even need to take a look into these files and directories.
