A kernel without any programs to run on it is useless. Most of them have different installation procedures and processes. They don't all include the same software. For the most part though, a core set of programs are included with all distributions. Some distributions are more agressive about including the latest versions of software and the kernel, while others may tend towards cautious adoption.
Some distributions install the same program to different places in the directory tree.
Another difference is where configuration files are stored. Probably the most important difference to the end user is in package format. It is the Linux kernel that supports your computer's hardware. All distributions use the same Linux kernel. Thus, no distribution has better hardware support than others.