The 4+1 view model was created by Philippe Kruchten in 1995. The author then claimed it is intended for "describing the architecture of software-intensive systems, based on the use of multiple, concurrent views." Its name comes from the views it consists of.
This model is widely known since it has been on the market for so long and does its job. It's well suited for bigger projects and while it can be used for small- and medium-sized ones as well, it can also turn out too complex for their needs (especially if they're written in an Agile way). If that's your case, you should try out the C4 model described in the next section.
A downside to the 4+1 model is that it uses a fixed set of views, while a pragmatic approach to document architecture would be to choose views based on the specifics of your project (more on that later).
A nice upside, on the other hand, is how the views link together, especially when it comes to scenarios. At...