Form 11 treatment of buying & selling shares

First time filling a form 11 and getting there slowly!

If you have bought and sold shares occasionally e.g. in different companies over the course of the year and have simply increased or decreased a position in those companies without ever disposing of all your shares owned how do you get all this information across in the Form 11.

I find quite a number of references to shares / securities and assets acquired and capital gains etc right across the form and am just confused as to what figures to put where. Some examples of the references I see are:

Section D. 219b = Taxable Benefits, Shares / Securities
Section L. 801 = Capital Gains,Description of Assets - Quoted & Unquoted
Section M. 817a = Chargeable Assets - Shares (quoted and unquoted)

Like everything it is probably simple when you know but if anyone could provide some direction it would be greatly appreciated!

Section 219b is only if you acquired shares through your employment. e.g. awarded shares in company as a bonus.

Section 801 - here you input consideration on the shares you have sold during the year. Section 807 you input the gain on the disposal of these shares.

Section 817a - here you input consideration on the shares you have purchased during the year.

Eldorado - Thanks for taking the time to reply. Your layman definitions help and I will re-look at those sections of the form tonight. Cheers!