A suspended possession order is essentially a second chance. Rather than requiring you to leave immediately, the court sets terms that let you stay if you keep to them. This is most commonly used in rent arrears cases where the court believes you can catch up over time, and is more likely when the landlord has used a discretionary ground.
The conditions are typically straightforward: pay your rent on time going forward, plus an additional monthly amount towards the arrears. As long as you meet these conditions, the possession order stays suspended and you remain in the property. If you fall behind again or breach the conditions, the landlord can apply to the court to enforce the order, often without needing a full new hearing.
If you're on a suspended possession order and your circumstances change (for example, you lose your job or become ill), you can apply to the court to vary the conditions, such as reducing the monthly arrears repayment amount. Don't simply stop paying, as the landlord will be able to enforce the order.