What are they referring in outputs?

[Little Mouse]

I had lost my earlier wallet due to a system crash and couldn't recover it. So, I had a new install of the Electrum wallet. I can't remember if I have seen this in an earlier version or not, maybe I didn't notice lol.
In the following image, for the output section, there are 3 figures. The first one is referring to the block number and the last one is referring to the output number. What about the amount in the middle- 2803? I can't find any information about this. The same applies to the input too which is 208.

[hosseinimr93]

The first number is the number of block in which the coin has been created.
The second number indicates the location of the transaction in the block. (It starts from 0)
The third number indicates the location of the output in the transaction. (It starts from 0)

790548x208x4 means that the coin has been created in block number 790548, in the transaction number 208 with output index of 4.
790551x2803x0 means that the coin has been created in block number 790551 in the transaction number 2803 with output index of 0.

[Little Mouse]

790551x2803x0 means that the coin has been created in block number 790551 in the transaction number 2803 with output index of 0.

Thanks for the explanation though I'm still confused a bit.
When I explored with the block number in the explorer, I can see #0 is the coinbase tx (mining reward) and then 2903 more tx. Out of these 2903 tx, my tx index is 2803, is that correct? If so, how is this indexing works? Based on the timestamp or based on the fee rate for which miners include a tx in a candidate block? Seems I'm very much a noob on the technical side of Bitcoin even though I'm a Legendary member here lol. I have to explore a lot to learn more.

[Cricktor]

Block 790551 has actually 2907 transactions and the indexing is based on sequential position of the transaction in the block. The first transaction in a block has index 0 and is always the coinbase transaction.

The sequence of the block's transactions is likely dictated by the way a candidate block is composed at first, where you first choose the transactions with highest fee rate per vB and fill the block's space with subsequently lower fee rate transactions. While hashing one might replace transactions of lower fee rate when higher fee rate transaction show up in the mempool. You can also vary the block header by changing the sequence of existing transactions in the candidate block as this would change the Merkle root of the block which is part of the block header.

[hosseinimr93]

When I explored with the block number in the explorer, I can see #0 is the coinbase tx (mining reward) and then 2903 more tx. Out of these 2903 tx, my tx index is 2803, is that correct?

Correct.

If so, how is this indexing works?

I am not sure, but I think miners are free to place transactions in the block in any order they want.

[o_e_l_e_o]

I am not sure, but I think miners are free to place transactions in the block in any order they want.

The only stipulation is that parent transactions come before child transactions. Usually this rule is irrelevant, because the vast majority of transactions have their parent transactions already confirmed in previous blocks. The time this does apply is in the case of CPFP or any other situation where a transaction spending an unconfirmed output confirms in the same block as its parent. In these cases, the parent(s) must be earlier in the block than the child(ren).

Having said that, although miners are otherwise free to order transactions any way they like, transactions are generally ordered in terms of fee rate, from highest to lowest, as the software building the candidate block simply picks transactions by their fee rate, from highest to lowest.