Home : Technical Terms : User Space Definition

User Space

User space is system memory allocated to running applications. It is often contrasted with kernel space, which is memory allocated to the kernel and the operating system.

Separating user space from kernel space protects the system from errant processes that could use up memory required by the operating system (OS). The result is a more stable system where memory leaks and program crashes do not affect the OS. It is an important aspect of sandboxing, which is common in modern operating systems.

When you open an application (or "excecutable file"), the OS loads the program and required resources into the user space. Any plug-ins and required libraries are loaded into the user space as well. If you open and edit a document, that file will also be temporarily loaded into the user space. When you save the file, the data is written from the user space to a storage device such as an HDD or SSD.

NOTE: The more RAM your computer has, the more user space is available. Having extra RAM allows you to run more applications simultaneously without your computer slowing down because of a memory bottleneck.

Updated: October 31, 2017

Cite this definition:

https://techterms.com/definition/user_space

TechTerms - The Tech Terms Computer Dictionary

This page contains a technical definiton of User Space. It explains in computing terminology what User Space means and is one of many technical terms in the TechTerms dictionary.

All definitions on the TechTerms website are written to be technically accurate but also easy to understand. If you find this User Space definition to be helpful, you can reference it using the citation links above. If you think a term should be updated or added to the TechTerms dictionary, please email TechTerms!