Please tell me the difference between tracheostomy and laryngectomy?

Different: Ostomy means opening, tracheostomy is an opening in the trachea usually in the front as a temporary airway access. Laryngectomy is removal of the larynx. If the larynx is removed the only way to breathe is to saw the cut end of the trachea to the skin thus creating a permanent end tracheostomy.

Extent: A tracheostomy is placing a breathing tube directly through the neck into the trachea. It is usually done for patients who are on mechanical ventilation for a prolonged time. A laryngectomy is removal of the larynx (voicebox), usually due to cancer.