system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How does the stealth technology work on stealth aircraft? How ‘invisible’ are these aircraft to sensors? Some examples being the B-2 Spirit, and F-117 Nighthawk.
gpt
The stealth technology at present has two components. There is a coating of radar absorbing material (RAM) that prevents bounce back. This is the primary protection for the B2. There is also radar redirection by using finely angled surfaces to prevent a direct bounce back to the site. This is the primary protection for the F117.

Both will be defeated if the range to the source is low enough. Additionally, tactics have evolved specifically to defeat these airframes, such as using airborne radars to beam and ground receivers to look for "blank spots".