A fireplace grate is the metal grill with little legs that raises your logs off the ground or floor of the hearth. If you have an indoor fireplace, it likely came with a grate (if not, you can pick them up cheaply online). Grates are useful because they allow oxygen to circulate under the fire (fires burn hottest and best when there's plenty of air getting to them). But when we're building fires outside, whether in a fire pit, chiminea, or just in a ring of stones, we rarely lift the logs off the ground.
A wood fireplace grate can be used in outdoor fire pits and such, too, and the added oxygen flow can make it a lot easier to keep the fire going. It's also easier to find a place to stick newspaper and kindling where it won't be crushed by the weight of the logs.
So, if you're having trouble, just grab the grate from your indoor fireplace, use it for your outdoor fire, and see if it helps.