Live funding is the older model and the more demanding one. Because the firm's own capital is exposed, allocation is slower, position limits are tighter, and risk desks intervene. Traders in turn get real fills, real depth and results that transfer to trading their own money.
Many firms run a hybrid: evaluation and early funded stages in simulation, with a small number of consistent traders copied into live accounts through a trade-copier.
Example: a trader passes an evaluation and is allocated a live 2-lot limit. Their simulated results showed $0.5 average slippage per side; live, in the first minute after data releases, it is 2.5 ticks. Monthly net falls from $6,000 simulated to $3,400 live — the same strategy, honestly measured.
Related: sim-funded-account, trade-copier, funded-account, slippage