I want to focus on work while at work
Where do you work and what type of work do you do?
I work in an office doing billing for a big company.
Being dedicated at work is good. If you want to focus, you should eliminate distractions in your workplace. You'll be able to focus better and be more productive.
I can multitask. I can manage to play online, listen to music and do my work at the same time.
While you might be able to multitask, it's not good to play around online while you're supposed to be working. While at work you should do your best to concentrate on your responsibilities.