How long does a baby need to stand independently before taking those first few steps?

My son is a late walker at almost 13 months he’s still far from walking. However, over the last couple of weeks he’s started standing without support; he stood for 10-20 seconds today and even took a small unassisted step on a different occasion.

I feel like he’s still a long way off from walking but just wondered what other mum’s experiences are? How long were they standing unassisted for before they had the confidence to take steps? Do they need to stand for long periods or is it possible for them to walk if they can only stand for a few seconds at a time?

TIA