Docker images layers मा बनाइन्छन् — प्रत्येक Dockerfile instruction ले एक layer बनाउँछ, र Docker layers cache गरेर rebuilds लाई गति दिन्छ। Layers र caching बुझ्नु भनेको efficient Dockerfiles लेख्नको लागि महत्त्वपूर्ण हो जो छिटो build हुन्छन् र सानो images बनाउँछन्।
Layers — प्रत्येक instruction ले एक layer थप्छ
Each Dockerfile instruction (FROM, RUN, COPY, etc.) creates a read-only LAYER:
→ layers stack to form the image; layers are CACHED and SHARED between images
→ if a layer is unchanged, Docker REUSES the cached layer (skips rebuilding it)
→ Layer caching makes rebuilds fast — only changed layers (and those AFTER) rebuild.
