die Verteidigung
defense
The protection of someone or something against an attack.
Die Stadtmauer diente der Verteidigung gegen feindliche Angriffe.
The city wall served as defense against enemy attacks.

defense
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defense
The protection of someone or something against an attack.
Die Stadtmauer diente der Verteidigung gegen feindliche Angriffe.
The city wall served as defense against enemy attacks.

'Die Verteidigung' (defense) is the noun corresponding to the verb 'verteidigen' (to defend). The ending '-ung' turns the verb into a feminine noun that describes the action or the result. If you know the verb, you can easily understand the noun.
Die Soldaten üben die Verteidigung der Brücke.
The soldiers practice the defense of the bridge.
In a legal context, you can recognize this meaning from words such as 'Gericht' (court), 'Angeklagter' (defendant), 'Anwalt' (lawyer), or 'Staatsanwaltschaft' (public prosecutor's office). Here, the defense is the opposite of the prosecution.
Die Verteidigung konnte neue Beweise vorlegen.
The defense was able to present new evidence.
In a sports context, you can recognize this meaning from words such as 'Mannschaft' (team), 'Angriff' (attack), 'Tor' (goal), or 'Spieler' (player). Here, the defense is the part of the team that is supposed to prevent the opponent's goals.
Die Mannschaft hat Probleme in der Verteidigung.
The team has problems in defense.
To express the purpose or goal of protection, the preposition 'zur' is often used. A common fixed expression is also 'Selbstverteidigung' (self-defense).
Er kaufte ein Spray zur Selbstverteidigung.
He bought a spray for self-defense.
In a military or state context, 'Verteidigung' (defense) is often combined with words such as 'Land' (country), 'Ministerium' (ministry), or 'Budget' (budget). Examples are 'Landesverteidigung' (national defense) or 'Verteidigungsministerium' (Ministry of Defense).
Das Budget für die Verteidigung wurde erhöht.
The budget for defense was increased.
protection
'der Schutz' and 'die Verteidigung' both have to do with keeping someone or something safe from harm. 'Schutz' is more general and can also be preventive, for example protection from the sun, illness, or danger. 'Verteidigung' is used especially when there is already an attack or when an attack is expected. It sounds more active: you are repelling something. Learners may confuse the words because defense can be a form of protection. If there is no direct attack situation, 'Schutz' usually fits better.

Die Stadt bereitete die Verteidigung gegen den Angriff vor.
The city prepared its defense against the attack.
Beim Radfahren trägt Lisa einen Helm zum Schutz vor Verletzungen.
When cycling, Lisa wears a helmet for protection against injuries.