Online High School
Instead of physically sitting in class, you can take all the same courses online from the comfort of your own home and finish high school online. There are some courses that still require you to physically go to a building to take an exam or for some other reason, but these are considered to be hybrids. In the US, online schools are generally free if they’re run by the state.
Advantages of Finishing High School Online
No need to get up ridiculously early in the morning
No bullies
No mean teachers
No set time limits
… do I need to list any more? 
Disadvantages/Requirements of Finishing High School Online
You have to manage your time on your own (though this could be a good thing too)
People will probably argue that you’re not socializing enough
You have to be able to type well
The actual course and work that you do will probably be pretty similar to the stuff you do in regular school
Getting a high school diploma online
These are usually called “virtual schools” or “cyberschools”. Everything is done over the internet.
There are 4 main types of assignments. Assessments are the most common, and include students uploading files, usually created using wordprocessors or spreadsheets. Worksheets are also common, and can consist of multiple choice, matching, short answer, and other questions. Generally, grading is controlled by the teachers. Most questions from worksheets are auto graded by the computer, but if a response is needed for any question, the teacher must manually grade that portion of the assignment. (From Wikipedia)
How do I know if an online high school is accredited? – If you graduate from an accredited online high school, you will have as good a chance of getting into college as a student from a public school. This counts for the US though. Other countries probably have similar requirements.
How to find an online high school
Distance isn’t really an issue, but it’s generally a good idea to try to enroll in one that’s not too far away.
The easiest way to find an online high school would probably be to search Google for “virtual high school” and the name of the city nearest to where you live. This method tends to work best for the US. For other countries, you may have to experiment a bit with what you type in.