What are the practical differences between software engineering and systems engineering?

The term "Systems Engineer" was copied from the true discipline of Systems Engineering around the time of the http://dot.com boom.  Real systems engineering has been around for more than a century, and has simply been a term used in recent times by IT types in an incorrect fashion for the most part.  Real Systems Engineering is a discipline that involves the design, construction, testing, and troubleshooting of devices or machines that involve more than a single discernible component.  A great example where true systems engineering is a key discipline is  at NASA.  All of our space vehicles are very complicated and are made up of systems of systems.  There is the on-board computer subsystem for instance,  which has hardware and software components, some of which are user-interface components  like the flight computer and climate control, and unseen but critical diagnostic components that send and receive information to and from  mission control involving trajectory, temperature inside and outside the crew module, and health and status checks of all critical subsystems and the astronauts themselves.  Then there is the propulsion subsystem, involving the several stages of the rocket (in the case of the space shuttle, there was a main fuel tank and two solid rocket boosters, in addition to the main engines on the shuttle itself) The propulsion subsystem is designed by rocket scientists and built by mechanical, electrical, and systems engineers.  It also has diagnostics involving fuel levels, flow rates, and temperature.  All of these subsystems make up the system we called the space shuttle, Apollo, Gemini, etc -- the final product you see on the launch pad, complimented by the software and hardware at mission control that interfaces wirelessly with the shuttle or what have you.  A road vehicle such as a car is very similar- there's the engine system, braking system, the computer system, and the physical assembly itself.  Hopefully this gives you an idea of what systems engineering really is.  Systems Engineers in the IT arena are sometimes correctly labeled, as they are looking for a software and hardware person to build the block diagrams of the various IT system's sub-components, how they interact (usually via what's called API's- application programmer interfaces). But sadly in my looking at job postings i rarely see a Systems Engineer in the IT field be asked to be the big picture guy, looking at and making sure all the development of the software and h/w modules are passing the right info.  What I usually see as job duties for an IT systems engineer invokes lots of programming and that is a humongous distraction from being able to look at the big picture.  It's kind of like asking a Project Manager of a high rise building to put on work Gloves and pour concrete all day -- in that case, nobody is watching to see that the building as a whole is being constructed according to building design, government code, as well as ensuring its being done so in an efficient manner.

Software engineering = "deals with the design and implementation of the code". System engineering = deals with design of systems which usually includes software engineering and integration with existing systems/software. Example 1 (SW engineering) - designing and coding a new iPhone game Example 2 (SY engineering) -  designing, integrating (and coding if necessary) email infrastructure for email services that require fail-over, backup, security and network monitoring. Of course those examples are over-simplified and vary between companies.