The result of the query is assigned to "q"
db.GqlQuery is the gqlquery method in the db class
"SELECT * FROM Person " + means in english select everything from model Person
"WHERE last_name = :1 AND height <= :2 " + last_name is a field and :1 is the first variable (same with height and :2 - second variable) AND joins the requests
"ORDER BY height DESC", order by field height descending
"Smith", max_height) variable 1 and 2
q = db.GqlQuery("SELECT * FROM Person " +
"WHERE last_name = :1 AND height <= :2 " +
"ORDER BY height DESC",
"Smith", max_height)