Odoo stores most model metadata inside a few meta-models which allow both querying the system and altering models and fields on the fly over XML-RPC.
For example code like below.

models.execute _kw(db, uid, password, 'ir.model', 'create', [{
    'name': "Custom Model",
    'model': "x_custom_model",
    'state': 'manual',
}])
models.execute_kw(
    db, uid, password, 'x_custom_model', 'fields_get',
    [], {'attributes': ['string', 'help', 'type']})
{
    "create_uid": {
        "type": "many2one",
        "string": "Created by"
    },
    "create_date": {
        "type": "datetime",
        "string": "Created on"
    },
    "_last_update": {
        "type": "datetime",
        "string": "Last Modified on"
    },
    "write_uid": {
        "type": "many2one",
        "string": "Last Updated by"
    },
    "write_date": {
        "type": "datetime",
        "string": "Last Updated on"
    },
    "display_name": {
        "type": "char",
        "string": "Display Name"
    },
    "id": {
        "type": "integer",
        "string": "Id"
    }
}

Note- With the help of this code we will set inspection and introspection.