The blog post explains the differences between the Spanish verbs 'tener' and 'haber', both of which translate to 'to have' in English. 'Tener' is primarily used to express possession, attributes, age, past experiences, and emotions, while 'haber' serves mainly as an auxiliary verb to form perfect tenses and can also mean 'there is'. Understanding when to use each verb helps in mastering their correct application in various contexts.