What is different between "Leave to remain" and "Leave to enter"?

I received my T2 BRB and it stated "Leave to Remain".
My previous T4 BRB is stated "Leave to Enter".

Is there a different?

Leave to remain is a visa granted WITHIN the UK.

Leave to enter is a visa granted OUTSIDE the UK.

Hi, thanks for your reply.

So Leave to remain, apply in UK, meaning I can live in UK to remain in UK.

Secondly question (I should use the same post).
What is the meaning of the number below:
Restricted Work
Cxxxxxxxx

There is no meaning?

You can work but only for the sponsor who sponsored your Tier 2.

If you want to work elsewhere, you need to get a new sponsorship and go through the process of applying (within the UK).

i understand this.

WHat is the meaning of the number below "restriction of work".
Is there any meaning?

Cxxxxxxxx

It is likely the CoS number.

Thanks, you are correct.
Is CoS number.

For Tier 4 visa, under Remarks, there also a number there like XCxxxxxx
I presume is ATAS certificate number?

It's a probably a Tier 4 CAS number.

What are you looking for?

Just checked, is CAS details: Sponsor licence number.