Technically it just means a significant change in the capital structure. In context usually something like: exchange a bunch of debt for new equity, typically

Technically it just means a significant change in the capital structure. In context usually something like: exchange a bunch of debt for new equity, typically with high dilution for existing shareholders. So you avoid dying from that debt in the short term, gain a bit of breathing room to do necessary things (e.g. layoffs) and to fix what is broken in your business model before you start running out of money again. Maybe you are lucky and debt load was the biggest part of the problem - but probably not.