Dealing with spaces in filenames

Over the years, Linux and Unix cognoscenti haven’t used spaces in file and directory names. Instead of naming a directory My Pictures, you’d name it My_Pictures, my.pictures, or mypix. Why? Shells break a command line at spaces, and most shells also word-split the results of variable and command substitution. So a filename containing spaces can be split into pieces.
Shells also assign a meaning to most non-alphabetic characters. A file named odds&ends or cool!! can cause trouble if you aren’t paying attention.