Would agree with whole and term life explaination used above. It's generally not used as an investment for most people.
Side note: I recommend people purchase life insurance (term) at least enough to replace income even in a situation where both spouses work. From experience, a widow will not be able to continue their life as normal after the passing of a spouse, especially if it's sudden. I have had clients lose children/spouses due to accidents and they could not say the child's name in my office 1 year after the loss with out breaking down. They are typically an emotional mess for quite some time. I have seen people lose the desire to live. Life insurance is part of the FI planning process. Get enough to make the emotional transition for your spouse/children as easy as possible. More if you like. I know my wife would have a hard time trying to manage rental property, take care of the kids, and return to work; so I carry about 10 years of income replacement while my kids are young.
We typically don't think about the consequences of the loss until we see someone else go through that. The life insurance is there to give people time to grieve and replace income. Most don't consider the grieving part. They wrongly assume the living spouse can go back to work the next Monday (next week, or month) as if nothing has changed. Having personally seen it, people take a long time to return to their "new normal" life.
As far as whole life, I have seen it used more as a tax shelter for those who have exhausted all other tax shelters (SEP, 401k, etc). Example being a high income business owner who does not qualify for a ROTH or has no access to 401k, or may have fully funded the SEP. Once you get over $200,000; your saving options are reduced (not a bad problem to have).
For most people here, it's not a good use. Term is a better fit. People here are trying to be FI, so the need for life insurance in the far future may not be necessary unless there is an estate tax issue. Most here will not have that problem, because they don't need a tremedous amount of assests to reach FI.