Jul 11, 2022 · In PowerShell, a substring is a part of a string. You can create a PowerShell substring from a string using either the substring, split methods.. An example of a string is subdomain.domain.com.The substrings of subdomain.domain.com are subdomain, domain, and com.. In this Itechguide, I will teach you all you need to learn about PowerShell Substring.