If you don't intend to install large programs or have large photo or video libraries, 512GB of storage space is plenty. If you do, make sure you acquire at least 1 TB. Otherwise, you'll have to supplement MacBook storage with external devices, the cloud, or network storage.
256GB is sufficient for most basic utilities. Word papers, images, family movies, emails, and so on don't take up much space. Raw video or images (typically for editing purposes), recent AAA games, a vast collection of high-quality media files, and so on all take up a lot of space. It's important to consider how you're going to use your device before you buy it.
If you need more space than that, consider an external hard drive or memory card reader. They're not as convenient as having everything in one place, but they can be useful for storing large files such as music tracks or project folders. Some come with their own power supply so you don't have to worry about running out of battery life while transferring data.
It's also worth mentioning that the amount of space available on your device is also dependent on what you're using it for. If you plan to store huge videos or albums, then you'll need to get a device that has enough room for them. Otherwise, you might run out of space prematurely. The same goes for apps: if you have lots of games, books, or magazines you want to read at once, you might need a device that has enough RAM onboard.
In conclusion, 256GB is a lot of storage. Unless you have a very specific need for more space, we wouldn't recommend buying a device any larger than this.
Even if you plan on storing images, movies, or music on your iPhone, 256GB should be plenty. Devices like the MacBook Pro and the 4K iMac are advertised as powerful PCs that can edit video and photos. They require much more storage than Apple's iOS devices do.
The iPhone 6s and 6s Plus come with 64GB of storage, which should be more than sufficient for most people. If you need more space, there are several options: 128GB is the default option and costs $199; the 256GB model is also available for $249. There are some other storage sizes too, such as 512GB and 1TB. These prices include 8GB of memory-boosting cloud storage from iCloud.
You can expand the storage further by purchasing a memory card. For example, SanDisk offers 64GB cards for $119 and 128GB cards for $179. It's recommended to buy at least one external hard drive too, as iPhones don't have any built-in storage protection against virus attacks or natural disaster losses. External drives usually come in sizes of 128GB and 256GB, but some models offer larger capacities too.
Finally, you could consider buying multiple devices instead of using up all your storage space on one device. For example, if you need more space for apps and media, you could get an iPad alongside your iPhone.
Conclusion If you mostly save text files and photographs, 1 TB of storage capacity is plenty. However, if you intend to save a big number of movies, games, and other huge files on your PC, you need allocate at least 2 TB of storage space on your laptop. Otherwise, you will not be able to store all your content in it.