What on earth are these called?

[Superduperamateur]

So I moved into a house with a nice size garden...but my god its a mess the soil is full of litter and old concrete. It's just shocking, but it's that time of the year and I'm starting to have a crack at it. We're trying to tackle this raised section (see picture) but want to start by changing these broken old slabs of concrete that are containing the soil.
So for starters what are they called and secondly how do we tackle changing them... any advice so gratefully received.

 

[Woollie]

So I moved into a house with a nice size garden...but my god its a mess the soil is full of litter and old concrete. It's just shocking, but it's that time of the year and I'm starting to have a crack at it. We're trying to tackle this raised section (see picture) but want to start by changing these broken old slabs of concrete that are containing the soil.
So for starters what are they called and secondly how do we tackle changing them... any advice so gratefully received.

Looking at that from here...dig out around the slabs to remove them or dig away the edge of the soil so it does not collapse..but if it does it is not looking like it would do any harm..depends on how fit you are as well..I have been a digger all my life and if it needs moving I am there....but have had some back issues over the years....common of course....My husband has had also back issues and he is not a digger so just depends on the way we are...barge boards to hold back the soil again or what ideas you have to support the raised bed..Once done would be good for veggies or plants....

 

[Chillie6]

So I moved into a house with a nice size garden...but my god its a mess the soil is full of litter and old concrete. It's just shocking, but it's that time of the year and I'm starting to have a crack at it. We're trying to tackle this raised section (see picture) but want to start by changing these broken old slabs of concrete that are containing the soil.
So for starters what are they called and secondly how do we tackle changing them... any advice so gratefully received.

Hi @Superduperamateur and welcome to the forum
With my limited knowledge I would call it edging. I guess that they are holding back the soil behind. Do you want to keep that as a raised section?
They look like they may be paving slabs of some sort. If you want to replace them there are a number of alternatives. Depends what materials you want to use.
This b&q link shows paving edges https://www.diy.com/departments/out...Y592556.cat#icamp=SRD_Outdoor_PavingEdging_L4
This link gives you an idea of how to lay new edging

How to Install Garden Edging | Simply Paving

Partition perfection, garden edging sections off lawns while keeping grass and flowerbeds in check. Learn how to install garden edging yourself today.

www.simplypaving.com

Or you could go for treated wood as @Woollie suggests. Depends on the look you’re after. There are certainly plenty of videos on line that should be able to help you. Hope that helps.
Dont be shy in asking any follow up questions we are all here to help if we can