The valuation of a company including the most recent round of financing raised. If a company raised £500,000 at a pre-money valuation of £4.5m, the post-money valuation includes the funds raised, which would make it £5m. Post-money valuation is used to determine equity ownership %.
The valuation that a company raises funds at, excluding the value of the funds they are seeking in their current round. This is the valuation founders will tell investors, i.e. "We are raising £500,000 at a pre-money valuation of £4.5m". Pre-money valuation is often shortened to just "pre", i.e. "We are raising £500,000 at a £4.5m pre". When the £500k is raised, it is added to the pre-money valuation of £4.5m to create the post-money valuation.
Where a start-up is not generating any revenue. They may have no customers and still be developing their MVP, or they could have a launched product but are more interested in onboarding customers using it to learn from their feedback, as opposed to charging for it.
Follows the Friends & Family round, this round is the first time external investors are brought in. Some form of prototype or MVP is expected (but this can vary by sector). Typically angel investors make up most of this round, but SEIS/EIS funds and some very early-stage VC funds. Round sizes can vary, but generally this round seeks to raise £150-500k.
Private Equity (PE) as a general term refers to shares that aren't listed on a public exchange. PE funds are institutions that specialise in making large investments in late-stage companies.