Let’s begin by defining what we mean by boundaries and limits. As IT technicians, we’re used to jargon, but it’s a good idea to establish the terms that will be used to ensure we’re on the same page.
Boundaries are absolute limits that cannot be breached. This is a design choice by Microsoft.
Limits are suggested guidelines that have been settled on, and are affected by system performance and testing by the product team. These can go beyond the suggested Microsoft limits but, performance-wise, there could be repercussions elsewhere.
Thresholds are restrictions within which the default value can’t be exceeded, unless that value is explicitly modified.
These sorts of numbers were only made visible from SharePoint 2010 onwards and have apparently been grafted onto SharePoint to protect users from… well, themselves. The scenario in which this sort of protection could be deemed necessary is if, for example, one user was looking to view all 20,000 items on a list, thus slowing down everyone else using the platform. If you’re new to SharePoint, I recommend you take a look at our Start to Learn SharePoint blog series. This will help you get started, and give you many pointers on how to leverage the platform to your advantage.