Simplify the following text for a Grade 15 native English-speaking person.
Original: Stealth technology also termed LO technology ( low observable technology ) is a sub-discipline of military tactics and passive electronic countermeasures , which cover a range of techniques used with personnel , aircraft , ships , submarines , and missiles , to make them less visible ( ideally invisible ) to radar , infrared , sonar and other detection methods .
Simplified: Stealth technology also known as LOT ( Low Observability Technology ) is a sub-discipline of military electronic countermeasures which covers a range of techniques used with aircraft , ships and missiles , in order to make them less visible .