It's one of the better EDR (Endpoint Detection and Response) tools on the market. For enterprises, they are able to suck down tons of system activities and provide alerting for security teams.
For detection, when I say "tons of data", I mean it. Any background logs related to network activity, filesystem activity, command line info, service info, service actions and much more for every endpoint in an organization.
The response component can block execution of apps or completely isolate an endpoint if it is compromised, only allowing access by security staff.
Because Crowdstrike can (kind of) handle that much data and still be able to run rule checks while also providing SOC services makes them a common choice for enterprises.
The problem is that EDR tools need to run at the kernel level (or at a very high permission level) to be able to read that type data and also block it. This increases the risk of catastrophic problems if specific drivers are blocked by another kind of anti-malware service.
When you look at how EDR tools function, there is little difference between them and well written malware.
Crowdstrike became a choice recently for many companies that got fucked over by Broadcom buying VMWare. VMWare owned another tool, Carbon Black, which became subject to the fuckery of Broadcom so more companies scrambled to Crowdstrike recently.
I hope that was enough of a summary.