When you have to do hard work to support other people, you are "bearing a burden".
The word "bear" means "carry" in this instance. A "burden" is a heavy weight. You can use "bear a burden" to talk literally about carrying heavy objects, but it's mostly used metaphorically.
It's common to use the phrase "bear the burden" to talk about someone paying for something that supports other people. Here are some examples of things that you might describe as "bearing a burden":
- paying for your elderly parents's care
- taxpayers paying for students' education
"Bearing a burden" is a negative-sounding phrase.