user login information

Hello all

I'm trying to understand the difference between azure sign-in logs to query logon activity vs. Microsoft graph? In the azure portal i can only go back 30 days. However if using Microsoft graph i can go back over 1 year. The below query is showing me results for "LastsigninDateTime" and i am seeing dates as far back as 8/4/202. When using Azure AD sign-in logs i can only go back 1 month. Why the difference ?

function queryAADUserLastSignin{
$uri = "https://graph.microsoft.com/beta/users?`$select=Displayname,signInActivity,userPrincipalName,userType,externalUserState,externalUserStateChangeDateTime,creationType,createdDateTime,onPremisesSyncEnabled,accountEnabled,mail"
do{
$results = Invoke-MgGraphRequest -Uri $uri -Method GET -OutputType PSObject
$results.value | select displayname, userPrincipalName,userType,externalUserState,externalUserStateChangeDateTime,creationType,createdDateTime,accountEnabled, `
@{Name="lastSignInDateTime";Expression={$_.signInActivity.lastSignInDateTime}},mail
$uri = $Results.'@odata.nextlink'
}until ($uri -eq $null)
}

queryAADUserLastSignin | export-csv .\guest_export1.csv -NoTypeInformation