If there is an improvement in something, it becomes better. If you make improvements to something, you make it better.
improvement vs improvements Both 'improvement' and 'improvements' are correct, but they are used in different contexts. 'Improvement' is singular and refers to the act or process of improving something, while 'improvements' is the plural form and refers to multiple instances of improvement or changes made to enhance something.
The editor made some improvements to/in the article before it was printed. They spent the money on new kitchen cabinets and other home improvements.