Should label or value be bold?
Bold-face the label, rather than the value. When reading online, people tend to scan. Particularly so when looking for a specific detail. If the amount of bold is too large on your page, nothing sticks out.
What is a label in UI design?
A label is a static piece of text that people can read and often copy, but not edit. Labels display text throughout the interface, in buttons, menu items, and views, helping people understand the current context and what they can do next. The term label refers to uneditable text that can appear in various places.