Interior locks as the term suggests are locks that are meant for the interior of the vehicle. Locks on the inside include those on the glove compartment, steering column locks, and door locks. Generally speaking apart from design differences all locks on the inside work essentially the same. That said since the size and shapes of the designs will vary it's important to buy one which is of the same shape and size as the one being replaced. Fortunately, most if not all genuine locks come with a part number which can be used to find a replacement. An exact replacement with a manufacturer recommended lock will provide you with years of service life.
Most interior locks are very durable and can last a long time. However, constantly opening and closing the doors to the glove compartment for instance or locking and unlocking the steering column can cause them to wear out. Fortunately, buying replacements are not expensive and installing them is comparatively easy for a professional. All auto locksmiths can install interior locks and even fix ones that have minor issues.
Even though interior locks are not expensive buying branded locks is the key to ensuring that they last a long time. OEM and well known brands also offer warranties. That said branded locks can cost a bit more, but at car-parts.ie they are competitively priced regardless of whichever you buy.