Outward appearance or exterior look — how something (e.g., a building or object) appears from the outside (slightly formal/written).
新しいオフィスビルの外観が近代的で美しい。
The exterior of the new office building is modern and beautiful.
外観は古いが、中は改装されている。
The exterior looks old, but the interior has been renovated.
外観からはその設備の性能は判断できない。
You can't judge the performance of the equipment from its appearance.