die Reinigung
cleaning
The process in which dirt, dust, or stains are removed in order to make something clean.
Die wöchentliche Reinigung der Wohnung dauert immer zwei Stunden.
The weekly cleaning of the apartment always takes two hours.

cleaning
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cleaning
The process in which dirt, dust, or stains are removed in order to make something clean.
Die wöchentliche Reinigung der Wohnung dauert immer zwei Stunden.
The weekly cleaning of the apartment always takes two hours.

The noun 'die Reinigung' (cleaning) is derived from the verb 'reinigen' (to clean). The ending '-ung' turns the verb into a feminine noun that describes the process or result of the action.
Könntest du bitte das schmutzige Geschirr reinigen?
Could you please clean the dirty dishes?
Pay attention to the context to know whether the activity of cleaning or the shop is meant. When people say 'in die Reinigung bringen' (to take to the dry cleaner's) or 'aus der Reinigung abholen' (to pick up from the dry cleaner's), they always mean the shop.
Die Reinigung des Badezimmers ist heute deine Aufgabe.
Cleaning the bathroom is your task today.
When it refers to the process of cleaning, 'Reinigung' (cleaning) is often combined with adjectives that describe the type. Common examples are 'chemische Reinigung' (dry cleaning), 'gründliche Reinigung' (thorough cleaning), or 'tägliche Reinigung' (daily cleaning).
Nach der Party war eine gründliche Reinigung der ganzen Wohnung nötig.
After the party, a thorough cleaning of the whole apartment was necessary.
When 'die Reinigung' refers to a shop, it is used like other places. You take clothes 'in die Reinigung' (to the dry cleaner's; accusative) and pick them up 'aus der Reinigung' (from the dry cleaner's; dative).
Ich muss morgen meinen Anzug aus der Reinigung abholen.
I need to pick up my suit from the dry cleaner's tomorrow.
In technical or scientific contexts, 'Reinigung' (purification/cleaning) means freeing a substance from foreign matter. For example, people speak of 'Wasserreinigung' (water purification) or 'Reinigung von Rohöl' (purification of crude oil).
Die Kläranlage ist für die Reinigung der städtischen Abwässer zuständig.
The sewage treatment plant is responsible for the purification of the city's wastewater.
care
'die Pflege' and 'die Reinigung' can both be part of keeping something clean and in good condition. 'Reinigung' mainly means removing dirt, dust, or stains. 'Pflege' is broader: it can include cleaning, but it also means protection, maintenance, or measures for health and good condition, for example with skin, hair, furniture, or plants. The words can be confused because cleaning is often part of care. If something is only being cleaned, 'Reinigung' fits. If something is meant to stay beautiful, healthy, or functional over time, 'Pflege' is a better fit.

Vor dem Wochenende ist die Reinigung der Klassenräume besonders wichtig.
Before the weekend, cleaning the classrooms is especially important.
Hannahs Pflege der alten Holzmöbel dauert lange, aber sie sehen danach wieder schön aus.
Hannah's care of the old wooden furniture takes a long time, but afterward it looks beautiful again.