Cash is one of the great comforts of financial lifeCash is one of the great comforts of financial life. A cash ISA for short-term needs can be sensible (Alamy Stock Photo)This is where ISAs and pensions are often misunderstood. Their job is to move money from cash thinking into future-self thinking. A cash ISA for short-term needs can be sensible. A cash ISA for retirement in 25 years may keep the tax break while wasting the engine.