detailliert
detailed
Very exact and containing many details; thorough and precise.
Der Architekt präsentierte einen detaillierten Plan für den Umbau des Hauses.
The architect presented a detailed plan for the renovation of the house.

detailed
Loading your saved state.
detailed
Very exact and containing many details; thorough and precise.
Der Architekt präsentierte einen detaillierten Plan für den Umbau des Hauses.
The architect presented a detailed plan for the renovation of the house.

The adjective 'detailliert' (detailed) is the past participle form of the verb 'detaillieren' (to detail). Both words come from the French noun 'le détail' (the detail).
Können Sie den Vorfall bitte noch genauer detaillieren?
Could you please detail the incident more precisely?
'Detailliert' (detailed) is often used with nouns that describe information or plans. Common combinations are 'detaillierte Beschreibung' (detailed description), 'detaillierter Plan' (detailed plan), 'detaillierter Bericht' (detailed report), and 'detaillierte Informationen' (detailed information).
Die Polizei gab einen detaillierten Bericht über den Unfallhergang heraus.
The police issued a detailed report about how the accident happened.
'Detailliert' (in detail) can also be used as an adverb to describe a verb. It then means 'with many details' and often appears with verbs like 'erklären' (to explain), 'beschreiben' (to describe), or 'analysieren' (to analyze).
Der Zeuge beschrieb den Täter sehr detailliert.
The witness described the perpetrator in great detail.
exact / precise
'genau' and 'detailliert' are close in meaning because both have to do with precision. 'genau' mainly means that something is exactly right or done carefully. 'detailliert' means that many individual details are mentioned or shown. The words can be confused because a detailed explanation is often also precise. But a precise piece of information can be very short, for example a time. A detailed description is usually longer and contains a lot of information.

Kannst du den Unfall bitte detailliert beschreiben?
Can you please describe the accident in detail?
Im Park habe ich die genaue Uhrzeit unseres Termins notiert.
In the park, I noted down the exact time of our appointment.