Android Mobile Phone - Memory Limitations

[countrykid]

Being new this year to owning a smart phone, I didn't realise how much memory gets used up by the OS and even just a few basic apps. My Moto G and partners Moto E are both now displaying messages that we are close to having used up all internal memory - even though we only have some pretty basic apps and no music or videos stored.

I can add an SD card to increase capacity but have been told this wont help much as apps cannot be stored on the card, the card being mainly for portable storage of say photos, music and videos. Is it true that apps cannot be saved to the sd card? Our phones run Marshmallow which when inserting an sd card asks if you want to use the card as portable storage or adopt the card for internal storage. The latter seems to suggests it might be usable for apps???? I am aware that once the card is adopted for internal use, it cannot then be taken out and used on say a PC. Finally, is a class 4 card ok for internal storage or must it be class 10. Thanks in advance

[countrykid]

Update: I took a chance and inserted a class 4 micro SD card and opted for it to be used an internal storage. I migrated certain apps to the card and photos get stored on it. As predicted by HC4361 it has now started to "slow" the phone down. I now realise I should have used a class 10 card to help avoid this slowing down. What I need to do now before I get a new card and take the Class 4 one out, is move any data/apps back to the phone's own memory. I've moved the apps back but cannot find a way to move the photos. I can't take the card out and insert in in a card adapter to copy to PC as the card can now only be used in the phone. Any help to get the photos back to the phones memory would be appreciated.

I've looked through the phone's manual to try and find out what the biggest capacity card I can use with it eg higher than 32Gb but I can't find this out. Again any help appreciated.

[hc4361]

Upload the photos to Google Photos (in 'the cloud') then you can view them from anywhere or download them as you please

[countrykid]

Thanks HC. I found out by chance that its set up to automatically copy photos to Google Photos, so yes I could use that option. It looks like there's other data of some kind on the sd card but not sure what it relates to. Ideally I'd like a simple way to simply transfer whatever is on the card, back to the phone before I take the card out. Since posting my last question re max capacity, I've found out its 32Gb.