Feedback from parents on reports is usually:
I want to know what my child is doing at school
I want to know how my child is doing
I want to know how I can help them do better.
Most reports therefore have a bit at the beginning saying what has been studied. At primary this is usually more along the lines of topic plus PE plus page plus art etc. At secondary it's more detailed (eg this term we have looked at Victorian gothic and read Dracula)
This answers question 1
Parents then want to know how their child is doing. It's not considered good practice anymore to list where the child is in the class (and anyway that doesn't tell you very much - could be a very low or very high achieving class). With a few exceptions (gcse results, sats results, phonics check) schools generally report three levels.
At primary it's either meeting age related expectations (your child is fine) exceeding (your child is doing very well) or below (your child is not fine).
At secondary the student will have gcse targets generated from sats levels. So a kid who got low sats will have have targets or 3 or 4, a kid who got high sats will get gcse targets of 8 or 9. Schools then report whether the kid is on target to get those results.
This answers question 2 although a lot if people do find the secondary system confusing.
To answer question 3 there are usually some statements along this lines of "on this topic your child can do this but not that." So for example for maths we might say your child can add fractions but can't multiply them.
This means as a parent you know what to work on if you want to help your child improve.