If you are learning PHP because you hope to use it as a career, there are generally one of three categories you will fall under. You will be an employee, a contractor, or working for yourself. I am going to explain each in this article and some of the pros and cons of each type.
The most obviously way to work with PHP is to be hired for traditional employment. This means you are hired by a specific company to work on their projects for a set yearly salary or hourly wage. You don't really have any say in what you work on, but you do have steady employment and usually qualify for benefits such as health care. The major advantage of this type of employment is obviously the security of having work given to you, and knowing exactly how much money you will be making every month. The disadvantage is that you don't pick your projects, your projects are given to you. Depending on the nature of the company you are working for you may never see a complete project, you might just be working on small sections of contributing code. It is also possible that you work for a small company are the only person working on the code, and expected to perform not just PHP miracles, but all types of IT services.
The second option is to work as a freelancer. A freelancer hires out their services on a project per project basis. You are working for other companies but are not an employee of the companies you work for. As a freelancer you can pick and choose your projects. On the flip side, your earnings can vary greatly from month to month depending on what projects you are working on, and how much work you can find each month. Sites like freelancer.com or elance.com make it easier for freelancers to hook up with people needing services. The down side is that you can often be severely underbid by people who work form countries with different economies, or by students trying to build their portfolios. Remember when you are putting in bids on a project that your hourly wage should be more than what you'd expect to make if you were hired by a company, because you are not getting any of the extra benefits associated with employment.
The final way to earn money as a PHP programmer is to create software to sell directly to people and companies. This is probably the hardest way to earn a living, but may be the most fulfilling. With this method you get complete control over what you are doing. You don't have any guidance, so if you have trouble staying on task this might not be for you. In this type of work you may have to wear many hats. Not only are you the programmer but you may also be the designer, the marketer, and the tech support for your software. We live in a world were a lot of software is free, so you have to make sure your software is special if you want people to pay for it. Perhaps it does something unique, or greatly improves upon existing technologies. Make sure that you program in some anti-piracy, or you might find that your software becomes very popular and you don't make any money!
Everyone has different things they like about programming, different strengths, and different preferences. Don't be afraid to do more than one thing at a time. Perhaps you dream of working for yourself on your own software but need a steady paycheck. Then why not get a job and develop your own stuff in the evenings or on the weekends? No matter what you decided, good luck with your PHP career!