Query dsl span_or vs bool should

Hi! I have two "span_near" queries. What's the difference between bool->should and span_or? Does it affect on "index.query.bool.max_clause_count" limit or query performance?

{
    "span_or": {
        "clauses": [
            {
                "span_near": {...}
            },
            {
                "span_near": {...}
            }
        ]
    }
}

vs

{
    "bool": {
        "should": [
            {
                "span_near": {...}
            },
            {
                "span_near": {...}
            }
        ]
    }
}