Break problems on my car

I have a 1999 Honda accord DX and the thing you see in the picture start leaking break fluid I was just curious on what's a called so I can get it repaired it metal and leaking fluid on the side thank you Break problems on my car help

Looks like a union from a chassis hard line to a flexible line to feed brake fluid to a wheel. Just a flexible brake line, & they do wear-out after awhile.