@timestamp vs timestamp date field

Elastic Stack Elasticsearch
1

Is there any difference between using "@timestamp" and "timestamp" date fields? Does elastic optimize search using those fields across multiple daily indices, perhaps if it knows min and max timestamp for each index?

Currently, I'm using "timestamp", does that hurt my search speed in any way?

2

It doesn't matter, as long as it's mapped as a date field.

The former was something that the Stack used as a bit of an internal standard. But it's not a special field.