This is the 1323rd most frequent Japanese word.
軽い
Light
The word '軽い' refers to the physical weight of the bag, describing it as not heavy.
このかばんは軽いので持ち運びやすいです。
This bag is light, so it's easy to carry.
'軽い' in this sentence is used metaphorically, describing the seriousness of the issue as not trivial or insignificant.
その問題は軽いものではありません。
That problem is not a light one.
The word '軽い' here depicts the step as gentle and graceful, not forceful or heavy.