Resignation is the process where an employee gives notice to their employer of their intention to stop working for the employer.
An employee may have abandoned their employment when they are absent from work for an extended period of time without explanation. Not all unauthorised absences are abandonment.
A constructive dismissal is where an employee feels they have no choice but to resign.
An employer cannot force an employee to retire except in very limited circumstances.
An employer may end their employee's employment via a 'dismissal' eg for misconduct or redundancy, but a proper process must always be followed.
An employer must follow a fair process whenever they want to make an employee redundant.
When an employee is leaving employment, their employer must calculate their final pay.