How does default and max lease ttl effect a kv-v2 mount?

Hi, I’m working on creating kv-v2 mounts for various teams and trying to understand how the default_lease_ttl and max_lease_ttl effect secrets.

I understand how ttl and max ttl works for a token, but unsure what it means for a secret mount.

I’m working with this API endpoint

Here is an example payload,

    type: 'kv',
    description: `Key/Value secret engine mount for the ${team} team`,
    config: {
      default_lease_ttl: '1h',
      max_lease_ttl: '24h'
    options: {
      version: 2

And an example using the API,

curl -XPOST -H 'X-Vault-Token: secret' \
  http://localhost:8200/v1/sys/mounts/team-one \
  -d '{ payload mentioned above }'

In the example payload, the default_lease_ttl is 1 hour. Can someone explain what that means for a kv mount? Do secrets expire?