A Dharma talk (Sanskrit) or Dhamma talk (Pali) or Dharma sermon (Japanese: Hōgo (法語), Chinese: 法語) is a public discourse on Buddhism by a Buddhist teacher.
[1] In Theravāda Buddhism, the study of Buddhist texts and listening to Dhamma talks by monks or teachers are common and important practices.
In some Zen traditions a Dharma talk may be referred to as a teisho (提唱).
In its strictest sense, teisho is non-dualistic and is thus distinguished from a Dharma talk, which is a lecture on a Buddhist topic.
If it only corresponds perfectly with the teachings but does not meet the needs of the listeners, it's not a good Dharma talk; it's not appropriate.