What's better advair or flovent?

Different medication. While both medications are used daily to control asthma, one is not better than the other. In general in asthma management the goal is to use the least amount of medication necessary to control asthma symptoms. Advair is considered to be a stronger medication as it has two compounds an inhaled corticosteroid (ics)plus a long acting beta agonist. Flovent is only an ics.
It depends. Flovent is a corticosteroid inhaler. Advair also contains a corticosteroid, but also contains the long lasting bronchodilator Salmeterol. There is concern over the safety of Salmeterol because of studies showing increased deaths from a worsening of asthma when using it. Because of this Advair should not be used for mild asthma that can be controlled by Flovent and short acting albuterol.
Depends. If mono therapy with an inhaled steroid is effective in controlling asthma, Flovent is a fine medication. If symptoms are not controlled, combination medication (inhaled steroid with long acting bronchodilator) like advair is a reasonable option. Short acting medication (albuterol) is usual the backup or rescue medication.