Difference between durations in Index Recap

Hi @Malfoy,
When I run Blight, it gives me 2 different elements about duration : 
```
Indexes created: 1554.47 seconds.
The whole indexing took me 2128.43 seconds.
```
I don't really understand the difference between this two.
Which one I must read to know how much time Blight need to create index of my data ?

Thank you